The Radziwiłł family is a directly descended branch of the extinct Lithuanian noble Astikai family line.[3] Its first notable member, Kristinas Astikas (born 1363), a close associate of the Lithuanian ruler Vytautas, became Castellan of Vilnius.[4] The patronym Radvila arose following its use by his son Radvila Astikas and grandson Mikalojus Radvila.[4] A legendary version of the patronym's etymology associates it with a child raised by wolves (rado vilko).[5] The name has been primarily written in, and recognized by, the polonized version and spelling for several centuries.