Jacob, Banner Lord of Wassenaer, Lord Obdam, Hensbroek, Spanbroek, Opmeer, Zuidwijk and Kernhem was a Dutch nobleman who became lieutenant admiral, and supreme commander of the navy of the Dutch Republic. The name Obdam was then also spelled as Opdam. British contemporaneous sources typically refer to him as Admiral Opdam or Lord Obdam because it was not until 1657 that he bought the Wassenaar Estate from relatives and thus acquired its title. Modern Dutch sources sometimes less correctly insert a second "van" between "Wassenaer" and "Obdam" or use the modern spelling "Wassenaar".