Rembrandt's full name was Rembrandt Harmenszoon van Rijn. Harmenszoon means 'son of Harmen', and 'van Rijn' simply means 'of the Rhine' (i.e. his home was in the Rhine valley). These last two names both sound like surnames, but his father's name was Harmen Gerritszoon van Rijn and (as far as I can ascertain) the actual surname is van Rijn.
© Haydn Thompson 2017