Jewish Encyclopedia Volume 11 p577 states:

SUASSO: Spanish family, with branches in Holland and England. The following are the more important members (in chronological order):

Antonio (Isaac) Lopez Suasso: Resident of The Hague. For services rendered to King Charles II of Spain, that monarch in 1676 created Suasso a baron, his estate of Avernas de Gras in Brabant, now called "Cras Avernas." being made a barony. He was one of the most ardent supporters of the house of Orange; and when William III undertook his expedition to England in 1688, Suasso advanced him 2,000,000 gulden without interest and did not even ask for a receipt, merely saying: "If you are successful you may repay me; if you are not successful, I will be the loser." Frederick II of Prussia commemorates this instance of self-sacrifice as the act "of a Jew named Schwartzau" (Euvres Historiques," i. 152)