Dutch Captain: Jan Theuniszoon Sluys

Jan Theuniszoon Sluys served the Admiralty of Amsterdam. He took command of the Walcheren (30 guns, a crew of 90 sailors and 20 soldiers) in April 1637, replacing Pieter Meeuszoon Vloo. The Walcheren was a vessel of 200 lasts. He was a captain of the Amsterdam admiralty, where he presumably only served from April 1637 until 25 August 1645, when we learn that he had died. He fought in all the battles in the autumn of 1639, and in the last battle, had the honour to bring in the first prize. From Blauhulck, we learn that he had the nickname of Boer Jaep, a name that we would otherwise only associate with the Van Nes family, which can cause confusion. Sources:

1. Dr. M.G. De Boer, Tromp en de Armada van 1639, 1941.
2. Dr. F. Graefe, De Kapiteinsjaren van Maerten Harpertszoon Tromp, 1938.