Emperor Charles V escalated into battles that were won by the Emperor. As a result, Charles V spent Christmas 1546 in Heilbronn to attend the ensuing criminal proceedings. It is also Charles V who in 1522 changed the charter of the city and this charter survived almost unscathed until 1803.
During the Thirty Years' War the city and surrounding villages suffered badly. After the battle of Wimpfen in 1622, Neckargartach was burnt to the ground. In 1631 Heilbronn was occupied by imperial troops but the same year the Swedes succeeded in conquering the city. From 1644 through 1647, Heilbronn was again part of the Holy Roman Empire, but then French troops moved in and later those of the Electorate of the Palatinate. The city was not free of occupying forces until four years after the Peace of Westphalia of 1648. But already in the 1670s the city again became the stage for armed manoeuvres, until it was occupied by French troops in 1688. But while that occupation of the city only lasted several months, the French were only persuaded to leave the surrounding areas in 1693, after a large defensive army had been put into the field and fortifications had been erected.
During the 18th century the citizens of Heilbronn witnessed a boom. The archives tell that during that time almost all members of the city council had enjoyed some sort of formal education, Schiller and Goethe came to visit the city, and gorgeous buildings were being constructed in Rococo style.
On September 9, 1802 the city of Heilbronn lost its status as Imperial Free City when the troops of Duke Frederick I of W�rttemberg marched into town. The duke had lost his holdings on the left bank of the Rhine to France during the French Revolutionary Wars but had been compensated with areas on the right bank. This is how Heilbronn together with other formerly Imperial Free Cities became part of W�rttemberg in 1803. Heilbronn became the seat of an Oberamt (district), and the four Imperial Free
