The Nazi movement, which had been growing ever more threatening since the end of the 1920s, was fought with ever greater vigour, but ultimately in vain, primarily by the parties and organizations of the labour movement. Although much less frequently, representatives of the middle classes and in particular those from the Catholic sphere had also taken a clear anti-Nazi stance at the time, sometimes with quite clear words. In Wiesbaden, as in many other places, some of them even took part in the large protest manifestations of the two Social Democrat-dominated Republic Protection Organizations Reichsbanner Schwarz-Rot-Gold and Eiserne Front against the transfer of power to Hitler by Reich President Paul von Hindenburg on 30.01.1933 and in the days that followed.

The Communists also organized several mass marches and rallies against this, but were unable to make any impact beyond their own political camp. The anti-fascist united front propagated by both the SPD and KPD at the time failed due to the abysmal political and ideological divisions between the two left-wing parties. The Communists continually attacked the Social Democrats as "social fascists" and "traitors to the workers", while the former were attacked no less harshly by SPD speakers and publicists as "Nazi-Kozis". The KPD only saw its decidedly anti-social democratic animosity confirmed by their constant rejection of their demands for a general strike directed at the SPD, the Iron Front and the social democratic trade unions.

In the spring of 1933, large sections of the bourgeois camp, which by then had already become increasingly skeptical or even hostile towards democracy or had become extremely disappointed with it, moved closer to the course of the new rulers. A strong fear of a supposedly imminent Bolshevik revolution also played a significant role in this. On March 23, the conservative and liberal parties in the Reichstag all voted in favour of Hitler's "Enabling Act" and thus gave their consent to the establishment of his dictatorship. Only the Social Democratic parliamentarians, including the former SPD party secretary and city councillor as well as the former state councillor at the provincial administration in Wiesbaden and deputy Prussian plenipotentiary to the Reichsrat, Otto Witte, refused to do so. The KPD Reichstag deputy for the same constituency 19 Hesse-Nassau, the General Secretary of International Workers' Aid and chief propagandist of the Communist International Willi Münzenberg, on the other hand, had fled from Frankfurt via Mainz to Saarbrücken immediately after the Reichstag fire on February 27, in order to continue his journalistic-propagandistic fight against Nazi fascism from Paris.

All other communist Reichstag members were equally unable to take part in this vote, as their mandates had all been annulled and they had also either fled or been imprisoned. This also applied to a good fifth of the Social Democratic parliamentarians, such as Toni Sender, a member of the Reichstag from Dresden-Bautzen, who came from a Jewish family in Biebrich on the Rhine and who fled completely destitute to Czechoslovakia on March 5, the day of the Reichstag election, before emigrating to the USA for good at the end of 1935.

As everywhere in Germany, a Nazi terror against functionaries and activists as well as institutions of the workers' parties and trade unions, the brutality and rigor of which had previously hardly been thought possible, had been raging in Wiesbaden since 1933. In the first months of Hitler's rule, the press, which had not yet been brought into line, was full of reports of devious, mostly armed Nazi attacks on political opponents, often resulting in injuries and even serious injuries. The homes of well-known SPD and KPD members were repeatedly raided. Many of them were dismissed from their municipal and other jobs. Shortly before the last Reichstag elections, numerous communists, including the city councillor Paul Krüger, were locked up in the police prison until they were able to secure their release through a week-long hunger strike. The KPD's office was closed, its press banned and it was no longer allowed to hold events. The SPD was soon silenced in the same way.

The factory workers' home in Mainzer Straße and the trade union building in Wellritzstraße were occupied, searched and demolished by SA men and members of the National Socialist factory cell organization, the latter for the third time on 2 May, namely in the course of the nationwide smashing operation against the entire social democratic trade union movement.

On March 24, the SPD city councillor, trade union secretary and local leader of the Reichsbanner and Iron Front, Konrad Arndt, had been stabbed and survived seriously injured. At the same time, Otto Witte faced open death threats, while the Jewish milk merchant and SPD cashier Max Kassel was shot dead in his apartment at Webergasse 46 on April 22. On May 16, Otto Quarch was shot while fleeing from SS men, which resulted in his death four days later. Dozens of workers' functionaries were deported to the SA detention center hastily set up in the former mint on Luisenplatz or to their beating cellar in Lessingstraße. The communist Karl Müller was shot there on August 19 of that year, as he too had allegedly attempted to escape.

Following the ban on the SPD's activities on 22 June 1933 and the subsequent party ban on 14 July, several Social Democratic groups were nevertheless able to maintain a certain degree of political cohesion while observing conspiratorial rules. In the early days, a distribution network for anti-Nazi literature was organized, especially for the new party organ "Sozialistische Aktion", which was obtained from the party executive committee, which had moved to Prague. But as early as autumn 1935, Georg Feller and Albert Markloff, who had organized the local Reichsbanner resistance since spring 1934, were arrested as part of a large-scale arrest operation against the illegal SPD district of Hesse-Nassau, which affected over 120 Social Democrats in the entire Rhine-Main region. As both of them resisted interrogation, the 50 or so supporters who had been associated with them in Wiesbaden remained undetected. At the beginning of 1936, Feller was sentenced to two and a half years in prison, after which he remained imprisoned in Buchenwald concentration camp until mid-1940. Markloff was sent to prison for two years.

The illegal SPD money collection point run by Max Meinhold in his tobacconist's store in Bleichstraße to support politically persecuted people and their relatives was not exposed until the end of the "Third Reich". A resistance group around Georg Buch, which had existed since 1933 and consisted mainly of former members of the Socialist Workers' Youth, initially with 30 to 40 members, had almost completely sealed itself off from the outside world, which is why it was only broken up by the Gestapo at the beginning of 1941 after an anonymous complaint. In contrast, the opposition meetings and hikes organized by the Naturfreunde from 1934-41 were never uncovered. The same applies to the conspiratorial Wiesbaden base led by former Worms police director Heinrich Maschmeyeras part of Wilhelm Leuschner's Reich-wide anti-Nazi network of confidants for the civilian flanking of the attempted coup by opposition military officers on July 20, 1944.

In the same way, the Wiesbaden contact between Prof. Dr. Adolf Reichwein and the former young teachers' chairman of the disbanded Prussian Teachers' Association, Walter Jude, which probably took place in 1943 to broaden the personnel of this ultimately extraordinarily widespread civilian resistance structure, went unnoticed, as did the fact that the former elementary school teacher and adult education centre director Johannes Maaß had been working on extensive reform pedagogical concepts for the post-Hitler era here since the previous year, despite being banned from writing.

At the beginning of the "Third Reich", the communists considered themselves to be in a pre-revolutionary situation and therefore initially relied on mass resistance with extremely high losses. In addition to pure party groups, which were usually set up conspiratorially according to the five-group principle and later according to the three-group principle, there were also groups from the secondary organizations Rote Hilfe and the Communist Youth League. In addition, smaller KPD company groups were active in a number of Wiesbaden companies, such as the Kalle company, Chemische Werke Albert, Maschinenfabrik Wiesbaden and Deutsche Reichspost.

The political guidance of the Wiesbaden KPD was provided by the district leadership operating from Frankfurt. The central and regional anti-Nazi propaganda materials were soon also obtained from this office, after the relevant leaflets and newspapers had initially been hectographed here. However, serial arrests brought the communist resistance to an almost complete standstill in the second half of the 1930s. Some Wiesbaden communists who had fled abroad to escape the Nazis, such as Günther Berkhahn, Heinrich Ofenloch, Hans Thamerus and Paul Schmiedel, fought as volunteers in the ranks of the International Brigades in the Spanish Civil War against Franco's fascism. Anton Lindner, who was deployed there as a gunner from 1937 to early 1939, finally fell at Whitsun 1944 as a member of the Gaullist partisan unit "Bir Hakeim" in a sacrificial battle against Wehrmacht soldiers in Hures-la-Parade in southern France.

Probably the best-known local resistance structure of the KPD was the Hoevel-Noetzel group. This group was first formed in 1938 and since then established conspiratorial contacts in the Rheingau region, Koblenz and as far as the Ruhr area, where it was also possible to forge links with some members of the Wehrmacht. Arrested at the end of 1941, Andreas and Anneliese Hoevel, both former top functionaries of the KPD district of Hesse-Frankfurt, were sentenced to death on June 26, 1942 and executed on August 28 of the same year in Frankfurt-Preungesheim prison. Margarethe Noetzel got away with a six-year prison sentence. Several other members of the group were also sentenced to prison terms. Adolf Noetzel was found hanged in his cell in the Wiesbaden police prison on December 6, 1941, following horrific torture.

During the war, small communist groups were again active in several factories, providing support to the foreign forced laborers and prisoners of war deployed there whenever the opportunity arose. The reconstruction committee founded in the spring of 1945, which explicitly saw itself as representing all anti-national socialist forces in the city, was rooted in a cross-party resistance group, which was nevertheless dominated by liberal democrats, around Heinrich Roos, who at the time was a friend of Adolf Noetzel and Andreas Hoevel and later became the CDU city treasurer. It was a community of more than 30 opponents of National Socialism that did not engage in any anti-Nazi propaganda activities, but was primarily dedicated to obtaining and discussing suppressed news and supporting persecuted people, not least Jewish people in need. The detective commissioner Werner van Look and the telegraph inspector Karl Schneider persistently sent the group warnings of impending Gestapo persecution.

Through several people, including the later CDU politicians Ferdinand Grün and Erich Zimmermann, there were indirect informal connections even to the civilian wing of the resistance movement preparing the attempted coup of July 20, 1944. The solidarity community, which remained nameless during the Nazi era, was also networked with Heinrich Maschmeyer and his SPD comrades in Wiesbaden via intermediaries. The businessman Ludwig Schwenck also maintained contact with Captain Hermann Kaiser in Berlin through conspiratorially coded correspondence. This clearly bourgeois resistance circle with further connections to the church opposition as well as to some other representatives of the workers' resistance was never tracked down by the Gestapo.

In those years, many middle-class, but over time also increasingly social-democratic and then even communist opponents of the Nazis sought solace and mental reassurance by attending church services and other events organized by pastors critical of the regime from both major churches. Among Protestants, the opposition "Confessing Church", to which at least several hundred believers in Wiesbaden belonged, was particularly popular. Quite a few of its pastors and laymen were relentlessly persecuted by the anti-church repressive regime.

A particularly tragic example of this is Dr. Hans Buttersack, the decidedly national-conservative legal adviser to the Wiesbaden confessional parishes, who presumably died in the Dachau concentration camp on 13 February 1945. Despite the Concordat concluded between the Holy See and the German Reich on July 20, 1933, many Catholic clergymen and parishioners were also prosecuted, often in draconian ways. The same applied to the small religious community of Jehovah's Witnesses, which had been banned since mid-1933 and whose members consistently refused to give the Hitler salute, to be active in Nazi organizations or to perform military service, which was also often punished with the harshest penalties.

Certain forms of non-conformist or resistant behavior were also evident in youth culture. These included several groups of the bourgeois Nerother Wandervogelbund, whose activities only came to a standstill a few years after its official dissolution in mid-1933 as a result of police and criminal prosecution. The so-called Swing Youth was also massively combated during the "Third Reich" as an alleged "phenomenon of neglect". Followers of swing joined together to form the Hot Club Wiesbaden and met up until the war years, preferably on Mauritiusplatz and in the Park Café. They were repeatedly taken by force to the Gestapo headquarters in Paulinenstraße to be harassed or given a "proper German haircut".

In addition, the bourgeoisie and the workers' parties provided individual assistance to those persecuted for political, religious and racial reasons, of which only a few examples can be given here: The two Albert directors Dr. August Amann and Hermann Glock protected members of the workforce who were in danger because of their well-known social-democratic views. The communist Rudi Leitem was involved in two successful rescue operations for women persecuted because of their Jewish origins. Naftali and Sofia Rottenberg, who had only converted to Judaism after her marriage, owed their survival to the non-Jewish couple Ria and Theo Bach, who were related to them and hid them from the Gestapo until the end of the war. And Elisabeth Ritter, the then wife of the owner of the excursion café of the same name in the "Unter den Eichen" area, together with her later husband Josef Speck, repeatedly provided the prisoners of the neighboring concentration camp sub-commando of the SS special camp Hinzert with various types of support that were vital for their survival.

Two other opponents of the regime who came from the Wiesbaden bourgeoisie were involved in a leading position in Berlin in the military and political preparations for the coup plan of July 20, 1944, namely the former Chief of Staff of the Army, Colonel General Ludwig Beck, who was intended by the conspirators to be the head of state of the non-Nazi Reich government they had planned, and Captain Hermann Kaiser, who might have become State Secretary in the new Ministry of Culture. First Lieutenant Dr. Fabian von Schlabrendorff, who acted as a courier between the resistance circles at the front and those in the home army and who was also involved in the famous attempt to assassinate Hitler in Smolensk on March 13, 1943, was in contact with both of them.

While Schlabrendorff barely escaped with his life, the legal scholar Dr. Hans John, who had also been involved in the "July 20" preparations in the Reich capital and had previously belonged to the small Wiesbaden branch of the League of Proletarian-Revolutionary Writers, was shot by an SS firing squad shortly before the end of the war. His brother, Dr. Otto John, who was even more involved than John, was employed as an in-house lawyer in the main administration of Deutsche Lufthansa and managed to escape from Berlin via the Iberian Peninsula to Great Britain on July 24, 1944.

In the Deputy General Command XII Wiesbaden itself, apart from the Chief of the General Staff, Major General Erwin Gerlach, at least the core of the so-called Führer Reserve is said to have been privy to the coup preparations. After the failure of the coup d'état, there were also several summary executions here, as contemporary witnesses have reported. In addition, some of the people who were arrested in Wiesbaden in the summer of 1944 as part of the Reich-wide "Gewitter" or "Gitter" arrest campaign against former SPD, KPD, Zentrum and trade union officials and who were then mostly sent to Dachau concentration camp did not survive the "Third Reich".

In the final months of the war, a so-called Illegal Committee for the Rapid Termination of the War drew attention to itself in several cities in the Rhine-Main region by posting slogans on walls, which cooperated with escaped prisoners of war who had then gone into hiding and is said to have had a conspiratorial regional headquarters in Wiesbaden. This was certainly not the case, but Heinrich Roos and some of his friends were connected to various leading figures in the city administration who, in close cooperation with the military district commander and last combat commander of Wiesbaden, Colonel Wilhelm Karl Zierenberg, thwarted the implementation of the Nazi destruction and evacuation orders, which would certainly have claimed many more victims among the civilian population.

It was thanks to the courageous actions of these citizens, including board member Fritz Reeg, the then city treasurer Dr. Gustav Heß, general director Christian Bücher and director Dr. Carl Stempelmann of Stadtwerke Wiesbaden AG, who risked their lives in doing so, that the city was handed over to the US Army a few days later largely undestroyed.