The House of Radziwiłł (; ; ; ) is a powerful magnate family originating from the Grand Duchy of Lithuania and later also prominent in the Crown of the Kingdom of Poland. The family was founded by Radvila Astikas, but over time it split into many branches, such as the Biržai-Dubingiai and Goniądz-Meteliai lines. However, most of the branches became extinct by the 18th century, with only the Nesvizh-Kleck-Ołyka line surviving to this day. Their descendants were highly prominent for centuries, first in the Grand Duchy of Lithuania, later in the Polish–Lithuanian Commonwealth and the Kingdom of Prussia. The family produced many individuals notable in Lithuanian, Polish, Belarusian, German as well as general European history and culture. The Radziwiłł family received the title of Reichsfürst (prince) from the Holy Roman Emperor in the mid 16th-century. The Nesvizh Castle complex, maintained by the family between the 16th century and 1939, is a UNESCO World Heritage site. Name and origin The Radziwiłł family is a directly descended branch of the extinct Lithuanian noble Astikai family line. Its first notable member, Kristinas Astikas (born 1363), a close associate of the Lithuanian ruler Vytautas, became Castellan of Vilnius. The patronym Radvila arose following its use by his son Radvila Astikas and grandson Mikalojus Radvila. A legendary version of the patronym's etymology associates it with a child raised by wolves (rado vilko). The name has been primarily written in, and recognized by, the polonized version and spelling for several centuries. The family descends from Lithuanian bajorai-ducal courtiers who advanced considerably in the 15th-century politics of the Grand Duchy of Lithuania. Along with possessions of land near Kernavė, the family's traced place of origin, the Radziwiłł family also inherited the Trąby coat of arms. Three of Mikalojus' sons, Mikołaj, Jan, and Jerzy, went on to become the progenitors of the three known Radziwiłł family lines. The Radziwiłł family divided by branch: the Goniądz - Meteliai line the Biržai - Dubingiai line the Nieśwież (Nesvizh) – Kleck (Kletsk) – Ołyka line The Goniądz-Meteliai line became extinct by the next generation as Mikołaj's descendants consisted of one male heir, Mikołaj III, who entered the priesthood and became the Bishop of Samogitia, thus bearing no known offspring to extend the line. The Biržai-Dubingiai line was moderately more successful and produced some very notable state officials and politicians, but it also became extinct after Ludwika Karolina Radziwiłł's death in 1695.