Wiesbaden was first mentioned in 122 AD as "Aquae Mattiacae". At the end of the 4th century, the Alamanni and Franks conquered the town. The oldest evidence of Christianity in the city dates back to this time, which finally became established in Frankish times.

In the Merovingian-Carolingian period, the area around Wiesbaden is likely to have become a Frankish royal estate. This is indicated by the establishment of the Carolingian special royal estate ("Kunigessuntera"), first mentioned in 819. Einhard, statesman, master builder and biographer of Emperor Charlemagne, calls Wiesbaden "castrum quod moderno tempore Wisibada vocatur" ("the fortified place that has recently been called Wiesbaden") in 830. The settlement, which was thus given its modern name for the first time, was a suburb of the special royal estate, where a royal court and a royal church were located. This imperial estate in and around Wiesbaden was administered by a count. Around 1170/80, this function passed into the hands of the Counts of Nassau.

The medieval town at that time consisted of three settlement centers: The walled "narrower" town contained the specially fortified castle district and the houses of the servants and burgomans. Until 1508, this castle district alone was referred to as the "town". The roads from Mainz, Mosbach, Biebrich and the Rheingau converged in the suburb or "Flecken", which was secured by ramparts and ditches and was characterized by agriculture; the church and several noble farms were located here. The baths were located in the so-called Sauerland. All three settlement cores formed a single municipality under a single administration.

Around 1232, Wiesbaden was elevated to the status of an imperial city and was listed in the imperial tax list in 1241; according to this, the citizens were to be exempted from the taxes due in exchange for the expansion of the city fortifications. Wiesbaden was referred to as "imperatoris civitas" for the last time in 1242. In this year, the city, loyal to the Hohenstaufen dynasty, was destroyed by the Mainz party and began its decline to an insignificant country town. In 1277/78, King Rudolf I of Habsburg enfeoffed the later King Adolf of Nassau with Wiesbaden in order to strengthen the position of the empire vis-à-vis Mainz. Apart from the decades around the middle of the 13th century, the House of Nassau was traditionally loyal to the emperor. Imperial favors for the imperial city, such as the right to strike Heller and dig for silver in Wiesbaden (1329), were not lacking. In 1348, King Charles IV solemnly confirmed the rights of the city lords for the first time. These included the town itself with all its "accessories", the mint, the Biebrich Rhine ferry and customs. This was followed in 1351 by a royal charter for Sonnenberg. In 1354 and 1367, the Nassauers had their minting rights confirmed. Wiesbaden was a largely agrarian town. The local craftsmen - the earliest mention of a shoemaker dates back to 1232 - only produced goods for local needs. Members of the upper class were probably the owners of the bathhouses, of which 26 are already known by name in the 15th century.

The religious center was the Mauritius Church, whose origins date back to the Carolingian period, although it was first documented in 1248. Surrounding the Mauritius church was the walled cemetery, where burials took place until the 17th century. A St. Michael's Chapel donated in 1330 with an ossuary in the basement completed this religious center. There were other chapels, such as a Marienkapelle "auf dem Sand" in the Sauerland, which dates back to the early 13th century, and a Georgskapelle, probably built around the middle of the 14th century between Michelsberg, Kirchgasse and Säumarkt, which was probably associated with one of Wiesbaden's noble courts. In the area of the old castle, people were content for a long time with a chapel bay "on the hall", which was dedicated to St. Anne. A separate castle chapel with the patron saint Mary Magdalene is mentioned in 1477. A chapel dedicated to Mary was located in the hospital at Kochbrunnen. It was destroyed during the Thirty Years' War, while the other places of worship fell into ruin after the Reformation and were demolished.

The first information about the town government can be found in 1280: The organ of municipal self-organization was the Schultheiß and seven Schöffen. The Schultheiß (also known as Erbschultheiß or, from the 14th century, Amtmann) was appointed by the sovereign; he was usually of noble rank, presided over the college of aldermen and was responsible for jurisdiction and administration. A municipal seal with a count's coat of arms and the inscription "Sigillum universitatis oppidi Wysebaden" ("Seal of the entirety [of the inhabitants] of the town of Wiesbaden") has been preserved from 1325. A new municipal seal was introduced in 1355 and remained in use until 1624. From 1438, there were two mayors, a jury mayor and an alderman mayor or Schultheiß - an indication that the citizens were given a greater say. In addition to the council, there was another representative body, the citizens' assembly. Topics of discussion included tax issues, matters relating to the use of pastures, the influx of new citizens, etc. Until the 18th century, there were a total of 22 regularly appointed officials, mainly in the area of "good policey": night watchmen, field marksmen, doormen, gatekeepers, etc.

Appointments were usually made by the municipal court, which was subject to the more formal supervision of the sovereign bailiff - the former mayor. It dealt with all the administrative tasks arising in a small town: Town defense, accounting, collection of taxes and fees, police matters. It was also responsible for the facilities that were to be shared by all citizens, such as the bakery and brewery, smithy, baths and the right to use certain parts of the field. In the 13th century, the town court met in the cemetery near the church, and hearings also took place in an "arbor" in front of the house of one of the aldermen or the mayor. Today's old town hall was built in 1609.

At the beginning of the 16th century, the town suffered a number of setbacks in its development. The first turning point was the Peasants' War, in which many inhabitants took part in May 1525. The anger of the citizens was directed against the town authorities, the clergy and the sovereign bailiff. They demanded the abolition of timber transportation for the castle and the free use of water, pasture and forest. After the uprising was suppressed, Count Philip the Elder revoked many of the town's privileges and restricted its liberties. In the following decades, the citizens tried to regain these, but were only partially successful. The Reformation took hold in Wiesbaden in the 1540s. In April 1547, the city was ravaged by a severe fire, which destroyed almost the entire building fabric as well as large parts of the city archives. Several other, albeit less devastating, town fires prompted the town court to appoint a night watchman towards the end of the century; fire regulations were also issued. During the Thirty Years' War, Wiesbaden suffered greatly from raids and quartering. The final peace came in 1648.

In 1605, Count Ludwig II of Nassau-Weilburg took over the rule of Wiesbaden. He seems to have intended the town to play a central role in the enlarged new territorial union and gave it a share of the customs revenue so that it could pay off the debts for the town hall building. Ludwig also confirmed the privileges lost since the Peasants' War. At the same time, his reign was one of consolidation of power: stronger control of the municipal bodies and the enactment of police regulations served to secure the subjects' tax payments and their moral renewal.

The accession to power of Prince Georg August Samuel zu Nassau-Idstein in 1684 was an even more significant turning point for the town. The new ruler's ambitious goals included the resettlement of new citizens, which was to be achieved through tax concessions and contribute to a revival of trade and commerce, as well as urban development measures and the construction of a summer residence on the banks of the Rhine in Biebrich. These projects were financed by increasing taxes on the old-established citizens, some of which increased fivefold. Within Wiesbaden, Georg August Samuel had new streets built with a closed construction method, enlarged the nave of the Mauritius Church and extended the ring of walls around the city. The construction measures were placed under the supervision of a princely foreman - one of many interventions in the city's administration which, together with dissatisfaction over rising taxes, led to inner-city unrest around the middle of the 18th century. The number of inhabitants increased from 644 in 1690 to 1329 in 1722.

In 1744, Biebrich Palace became the main residence of the Principality of Nassau-Usingen, while the seat of the central authorities was moved to Wiesbaden. Numerous civil servants and military personnel moved to the town and the population grew considerably. The central authorities made every effort to adapt life in the city to the requirements of a capital city. The safety, building and fire regulations issued from 1744 onwards, as well as the authorities' regulations on price and quality control for food and keeping the streets clean, should be seen in this context. The tax burden continued to increase and there was further unrest and conflict, especially in the middle of the 18th century. The opposition turned against the mismanagement of the council and the municipal court with the aim of restoring the old tradition of civic co-determination. Despite initial successes, however, it failed, the sovereign's control over the civic self-representative bodies was extended and they were incorporated into the territorial administrative hierarchy. A special police court was set up in 1757 to "keep the citizens, who were accustomed to disorder, in fear"; the penitentiary and workhouse founded in 1767, rigid price controls and the distribution of domain land to the population were among the disciplinary and structural measures taken by the provincial government. In the end, the local authorities were largely disempowered.

This paved the way for Wiesbaden's development into a modern city, for the integration of the city administration and the civic community into the state. This was all the more readily accepted by the population because at the same time, major efforts were initiated by the state to revitalize the city's economy. This included increasing Wiesbaden's attractiveness as a health resort, e.g. through theater performances by traveling acting troupes and by allowing gambling, as well as through the creation and maintenance of parks and promenade paths. Hygiene regulations for waste disposal, street cleaning and maintenance of the sewers were issued. In addition to his duties as a watchman, the town watchman was commissioned to organize square concerts. In 1769, Karl Fürst zu Nassau-Usingen founded Wiesbaden's first printing works, and a faience factory set up by him existed until 1795. In 1794, the city became the headquarters of the Prussian and Electoral Saxon armies and, after their withdrawal, had to accept the quartering of French troops, who only withdrew in 1799.

Around 1800, Wiesbaden had around 2,500 inhabitants and was still predominantly rural in character. In the following decades, however, modernity arrived: serfdom, corporal punishment and trade barriers were abolished and many technical innovations were introduced. The initiative to expand the town came from the state. The prelude to this development was the accession to the Confederation of the Rhine and the associated elevation of Nassau to a duchy in 1806. Within a short period of time, the cityscape changed fundamentally. In the course of the defeat of Napoleon I, the town once again became an assembly point for troops. After their withdrawal and despite the oppressive war debts, the expansion of the town and the development of cultural life continued. The connection to the German Customs Union in 1836 and the modernization of the infrastructure contributed to the increase in population and the general upswing of the city. Wiesbaden was the capital's center and a place of representation. It served as the winter residence of the Dukes of Nassau, while the Biebrich court residence remained a retreat for private princely life.

Until the edict on the new municipal constitution (1816), certain rights could be granted to citizens by sovereign act, but could also be withdrawn again. Anyone who had acquired citizenship was a citizen. Clergymen, civil servants, military personnel, court servants and the so-called Beisassen, independent persons without a household, mostly day laborers, did not belong to the citizenry. In 1816, the definition of citizen was expanded: The class of Beisassen was abolished. Now every male inhabitant was allowed to become a local citizen, provided his income was secure. However, preference was given to sons of citizens; those wishing to move in from abroad had to pay a higher fee. Only those who had citizenship were allowed to hold a municipal office.

At the head of the administration was the Schultheiß, who was appointed for life, bore the municipal seal, safeguarded the rights of the sovereign and the interests of the municipality and was responsible for the salaried employees working in the municipal administration. Twelve "friends of the council", who together with the Schultheiß formed the town council, represented the citizenry. As a result of the revolution of 1848/49, the Nassau municipalities were given extended rights, in particular the independent administration of their assets and the handling of the regulatory police. The Schultheiß was finally replaced by the mayor. Together with the municipal councillors, he formed the municipal council, whose meetings were open to the public. After the annexation of Nassau, Wiesbaden became the capital of a government district. A long-feared intervention by the new government was the abolition of the casino in 1872. However, the financial losses were limited and were largely compensated for by the visitor's tax introduced in 1870. On 01.01.1873, the spa operations with all establishments and the Sonnenberg castle ruins were transferred to municipal management. In 1873, the last relic of the old town fortifications, the clock tower, was demolished. The new town hall was built in 1883/87.

After a severe typhoid epidemic in 1885, a systematic sewerage and drainage system was built. New hotels, churches, hospitals and schools were built. In 1899, the State Library, the Picture Gallery and the Nassau Antiquities Collection were transferred to the city and were subsequently given new buildings. Other major construction projects included the main railway station, the new Kurhaus, the new theater and the Kaiser-Friedrich-Bad. Wiesbaden was a meeting place for the nobility and the moneyed aristocracy, headed by Kaiser Wilhelm II, who stayed here so often that Wiesbaden became the third Prussian city, alongside Berlin and Potsdam, to be granted permission to call itself a residential city. In the last decades of the 19th century, Wiesbaden had also become the preferred retirement home of wealthy private individuals. In 1913, 192,108 foreigners visited the city, almost twice the number of inhabitants.

The end of the decades-long upswing became apparent with the sudden halt in population growth in 1908 and the collapse of the building boom. Countless rented apartments built for stock stood empty. The spa trade stagnated as it now became fashionable to travel to the winter sports resorts of the Alps or the Riviera instead of the Taunus spas. The downward trend was exacerbated by the outbreak of the First World War, which hit the town particularly hard as a spa resort that relied primarily on foreign guests. A general economic decline was the result. Many hotels were confiscated and served as military hospitals. The end of the war brought no improvement to the situation: French occupying troops moved in and the freedom of movement of the residents was severely restricted. The town remained occupied until 1930.

At the end of October 1919, the city parliament was re-elected; for the first time, women had equal rights. At the end of 1925, the town became the headquarters of the British Army of the Rhine for four years. In November 1929, the High ➞ Inter-Allied Rhineland Commission moved its headquarters from Koblenz to Wiesbaden, the British troops withdrew and a French battalion moved back into the city in their place. The period of occupation brought further decline for the spa town, even though the incorporation of 1926 and 1928 gave it greater economic leeway. The occupying troops left on June 30, 1930. However, the hopes associated with this were not fulfilled, as the effects of the global economic crisis had long since been felt here too: The number of guests fell drastically once again, and the state insurance institutions and most health insurance companies completely stopped approving health cures for their members in the fall of 1931. Of the approximately 150,000 citizens of Wiesbaden, one in three lived on unemployment or welfare benefits. The number of job seekers rose from 8,000 in 1928 to 20,000 in February 1933. The city's financial situation was so hopeless that in 1930 and 1931 the government sent a state commissioner to set a compulsory budget.

The precarious economic situation encouraged the political radicalization of the population: in the Reichstag elections of 20.05.1928, the National Socialists achieved their first major success with almost 7,000 votes and rose to become the strongest party in the Reichstag elections of September 1930. Resistance to the Nazi dictatorship also arose early on in Wiesbaden, mostly supported by Social Democrats and Communists. Wiesbaden became a garrison town again: on October 5, 1936, the 3rd Battalion of the Infantry Regiment 38 moved in and the Kavalierhaus was designated as the headquarters of the General Command of the XII. Army Corps. The Deputy General Command XII was later to become one of the nuclei of the revolutionary movement of July 20, 1944. The barracks built on Schiersteiner Straße during the imperial era were further expanded.

Jewish businesses were also destroyed and synagogues burned in Wiesbaden during the Reich Pogrom Night of 1938. Over 1,500 Jews were deported and murdered. Overall, the city suffered less from the air raids of the Second World War than other major cities, but in February 1945, the city center, spa district and Quellenviertel were hit hard. Around 8,000 Wiesbaden homes were destroyed and around 500 people died. A short time later, the end of Nazi rule became apparent. On the night of March 28, 1945, the Wehrmacht and the last city commander left the city and American troops moved in around midday.

The Americans set the course for a reorientation of the former spa town into a city of authorities, publishing houses and films. The Hessian ministries were housed in the former town palace and the Kavalierhaus; the town council was only able to move into the provisionally restored town hall in 1951. On April 21, Georg Krücke, a lawyer who had been dismissed in 1933, was reinstated as the new Lord Mayor. The main problem was the supply situation. The rapid resurgence of the population exacerbated the situation: at the end of the war there were around 123,000 people, by June there were already 143,000 and by 1948 the number had risen to almost 200,000. From the beginning of 1946, food production fell continuously and the daily calorie quota dropped to 850 per person. The Americans tried to counteract this with care packages and finally with funds from the so-called Hoover Plan, but the situation only eased after the currency reform in 1948. The housing problem was almost as pressing as the food problem: 46 hotels and over 3,000 private homes had been confiscated during the invasion. Added to this was the steady stream of refugees. 1,000 apartments had to be provided for the officials of the new ministries. In response, the Gemeinnützige Siedlungsgenossenschaft was founded, which began work in 1946 with the construction of apartments in the Kohlheck housing estate. A major construction project was the large housing estate on Hainerberg for the Americans. By 1953, the town hall, Kurhaus and the destroyed Quellenviertel had been rebuilt. In the first election to the town council on 26.05.1946, the CDU and SPD won the most votes with around 41% and 38% respectively, and the previous Lord Mayor Krücke was replaced by Hans Heinrich Redlhammer.

A few weeks after the end of the war, several publishing houses relocated from Leipzig to Wiesbaden. Well-known film production companies moved to the Unter den Eichen site, and from 1963-85 ZDF used the studios here. Top film organizations moved into Biebrich Palace. Various higher federal authorities, the military area administration IV (1956) as well as banks and insurance companies settled in Wiesbaden. In 1960, the number of employees in the service sector was just as high as the number of employees working in industry, and Wiesbaden developed into a "city of civil servants". Further political decisions affected the development into a modern healthcare location and a congress city with the Rhein-Main-Hallen, built in 1957, as its center. With the last wave of incorporation in 1977, the city reached its greatest expansion, with a population of around 275,000.

The car-friendly city was also propagated in Wiesbaden. The main protagonist was the urban planner Ernst May. Decisive resistance came from the Wiesbaden Young Socialists, who organized signature collections and citizens' initiatives under the slogan "Save our city - now". In 1971, the May Plan was finally rejected. Since then, awareness of the importance of the historicist buildings has increased, most recently encouraged by the state monument conservator Gottfried Kiesow and his publications.