This was actually the legalisation of an existing situation, because the counts of Holland had charged tolls illegally since the start of the 11th century.
Dikes and dams were built and the border between Holland and the bishopric of Utrecht had to be determined.
There was a dispute between Floris and the bishop of Utrecht about a new dam in the Rhine at Zwammerdam in 1165, which had to be settled by emperor Frederick.
In 1170 a great flood caused immense devastation in the north and helped to form the Zuider Zee.
The county of Holland adopted from him the rampant lion in the coat of arms and the name of William.