 These ancient Lithuanian names are constructed from two interconnected stems, the combination of which has been used to denote certain beneficial personal qualities, for example "Jo-gaila" means "a strong rider".Although virtually extinct following the Christianization of Lithuania, they continued to exist as surnames, such as Goštautas, Kęsgaila, Radvila or in their Slavicised versions, as well as in toponyms.The existing surnames and written sources have allowed linguists such as Kazimieras Būga to reconstruct these names.