According to some family archives, Wassenaar means Wasser Herren, Sea Lords/Kings, which had been a traditional title that the invading Romans (under Caligula) had recognized while destituting the kings of Batavia.

The founding father of the Wassenaer family was Philip, who lived in the early 13th century and owned lands in Wassenaar (current-day spelling).

Dirk's younger brother Filips received Duivenvoorde Castle in 1226 and founded the branch van Duvenvoirde.

His son Philips III van Duivenvoorde (c. 1248 – after 1301) received the fief of Polanen (near Monster, South Holland) in 1295.

Jacob II van Wassenaer Obdam (1645–1714) married Adriana Sophia von Raesfeld in 1676, who inherited Twickel Castle near Delden.

At the beginning of the 19th century, all family members were granted the title of baron in the Kingdom of the Netherlands.