Salerno was the most important city of the Normans for half a century, but with the Norman conquest of southern Italy, the city of Palermo started to substitute Salerno as the most important city for the Normans. Indeed, Salerno played a little part in the fall of the County of Sicily, after the Emperor Henry VI's invasion on behalf of his wife, Constance, the heiress to the kingdom, in 1191, Salerno surrendered and promised loyalty on the mere news of an incoming army.