Würzburg was a Franconian duchy when, in 686, three Irish missionaries tried to persuade Duke Gosbert to convert to Christianity, and ditch his wife. Gosbert was mulling it over when his wife had the three bumped off. When the murders were discovered decades later, the martyrs became saints and Würzburg was made a pilgrimage city, and, in 742, a bishopric.
For centuries the resident prince-bishops wielded enormous power and wealth, and the city grew in opulence under their rule. Their crowning glory is the Residenz, one of the finest baroque structures in Germany and a Unesco World Heritage Site.
In WWII 90% of the city centre was flattened. Authorities originally planned to leave the ruins as a reminder of the horrors of war, but a valiant rebuilding project saw the city restored almost to its pre-war glory.