Heilbronn which would remain owned by that order until German Mediatisation in 1805. Starting in 1268, the order built the Deutschhof there as one of its residences. The church building of the order that was located on the premises was modified and expanded several times: First in 1350 it was expanded (Gothic), then it was remodeled in 1719 (Baroque), and in 1977, it was consecrated as a cathedral.
After the demise of the Staufen dynasty, King Rudolf I returned city status to Heilbronn in 1281 and installed a regal advocate to rule the city. In addition to the advocate he put a council in place that was headed up by a mayor. Around 1300, the first city hall was erected in the market place and the Kilianskirche (built on the foundation of the Michaelsbasilica) was expanded. The Neckar privilege gave the city the right to modify the flow of the river in 1333, which meant it now had the right to construct dams, harbours and mills. Because of the infrastructure thus created, Heilbronn became increasingly attractive to merchants and craftspeople during the 14th century whose influence had been growing and who were now demanding the right to determine their own fate.
In 1371 Charles IV, Holy Roman Emperor, issued a new charter to the city. Now Heilbronn needed to answer only to the Emperor and as such was an Imperial Free City. Craftspeople and merchants were now represented in its council and the villages of B�ckingen, Flein, Frankenbach and Neckargartach became part of Heilbronn's territory.
As an Imperial Free City Heilbronn kept seeing itself threatened by the ambitious house of W�rttemberg. A very close relationship with the Holy Roman Emperor and a treaty with the Electorate of the Palatinate that was in effect from 1417 through 1622 strengthened Heilbronn's position and kept W�rttemberg at bay. The political stability enjoyed by the city during the 15th century caused it to bloom and many of its historic structures trace their roots back to
