Willem van der Zaan was a Dutch Admiral. His name is often given in the 17th century spelling Zaen.
Portrait of Willem van der Zaan by Bartholomeus van der Helst
Funerary monument for Willem van der Zaan. Oude Kerk, Amsterdam. Bizot, Medalische historie der republyk van Holland, 1690.
The St James' Day Battle took place on 25 July 1666, during the Second Anglo-Dutch War. It was fought between an English fleet commanded jointly by Prince Rupert of the Rhine and George Monck, and a Dutch force under Lieutenant-Admiral Michiel de Ruyter.
Engraving showing the St. James Day battle August 4th, 1666, between English and Dutch ships
St. James Day Fight August 4th, 1666, by Wenceslaus Hollar