The Historic Pentagon has become the common name for a planning figure that shaped Wiesbaden's urban development in the first half of the 19th century, which was developed as an "overall construction plan" for the Nassau residential city by building inspector Christian Zais and approved and put into effect by decree of the ducal state ministry to the government on 17.04.1818.

The core structure of this neoclassical urban plan is the partially newly laid out streets of today's Taunusstrasse and Röderstrasse, Schwalbacherstrasse and Luisenstrasse, which were conceived as the framework for the city's expansion following Wilhelmstrasse, and - as a possible further expansion to the south - today's Rheinstrasse. Within this pentagon, the plan also described the street grid of what would later be known as the Bergkirchenviertel. In doing so, Zais drew on the idea conceived by Carl Florian Goetz in 1803/1805 to enclose Wiesbaden's historic maze of alleyways in a system of straight streets such as Friedrichstrasse and Wilhelmstrasse, which is connected to it at right angles. From this, Zais developed an urban planning figure in the geometrically clear form of a pentagon, whereby the entire city was embedded in the landscape like a classicist cube, bordered by wide, one-sided avenues, on the city sides of which "modern" classicist rows of houses formed a handsome city edge in front of the city center, which was perceived as outdated and unattractive, and rows of trees were to underline the transition to the landscape, as can still be seen today in the upper Wilhelmstrasse.

On January 6, 1818, Christian Zais presented a construction plan for the development of the town, only parts of which have survived, but whose accompanying letter already verbally contained the concept of what later became known as the Historic Pentagon. The government then commissioned him to develop this idea, and on March 3, 1818, Zais submitted a detailed report. The main plan he drew has not survived, but the meticulous, descriptive overall description of the future development of the town within the framework of this planning idea has. At the end of this description, Zais also dealt with the level between Wilhelmstrasse, which was only to be built on one side, and the Bierstadt slope, which he wanted to see preserved as a green space, a guiding principle that has survived all changes of opinion in urban development policy to this day in the form of the park on Warme Damm. The state government submitted this overall plan to the ministry with an approving vote. The government calculated 175,503 fl. as the sum of the subsidies and land compensation to be provided for the planned roads. The ministry approved the plan. However, it referred to the expected resistance of the estates against cash bonuses for construction projects in Wiesbaden and, for its part, held out the prospect of a ten-year tax exemption for construction projects on the planned new roads. As expected, the estates rejected the financial support for new private construction projects in the course of Wiesbaden's urban expansion. Nevertheless, the concept of this planning determined further building activity.

During the first half of the 19th century, the historic pentagon and the new Kurbezirk adjoining it at right angles formed the outer framework of the city as determined by urban development planning. For almost four decades from 1818, the city developed exclusively within this framework, until from the middle of the 19th century the dynamics of urban development forced it to transcend the set boundaries on a broad front in all directions. Although Christian Zais' urban development plan for Wiesbaden was therefore overtaken by new urban expansions from the mid-19th century onwards, the historic pentagon he conceived as the core zone of the city center is still clearly visible in the urban layout to this day.

Even after the annexation of Nassau in 1866 and during Wiesbaden's growth spurt in the Wilhelmine imperial era, the Historic Pentagon remained the attractive city center despite the quadrupling of the population and widespread development into a large city, and the necessary new, enlarged infrastructure facilities were predominantly built within, on or near these five streets or adjacent to the spa district, e.g. the theater on the southern edge of the city. For example, the theater on the southern colonnade, the new town hall on Schlossplatz, the state library, the main post office and the new museum on Rheinstraße, the fire department on Neugasse and the municipal hospitals 1876-79 adjacent to the pentagon on Schwalbacher Straße.

It was only during the expansion phase after the Second World War, as a result of the development towards almost complete individual motorization in Germany, that a number of superordinate supply functions for the inhabitants of the city were relocated to its periphery, above all large-scale shopping centers, but also, for example, the municipal hospitals between 1976 and 1984 to Dotzheim and the courts in 2009 to the new justice center on Mainzer Straße.

The central importance of the Historic Pentagon for the city's self-image and the long-term influence of this creation by Christian Zais on Wiesbaden's urban development is reflected not least in the fact that the city's pedestrian zone, conceived as a special metropolitan experience, was realized exclusively within this historic urban area.