Naiman Beg came to the Grand Duchy of Lithuania at the beginning of the 15th century as a member of an excellent fellowship of Tatar nobility under the command of Jalal ad-Din, the future (short-time) khan of the Golden Horde. They came to help the Lithuanian Grand Prince Vytautas the Great in his war against the Teutonic Knights. They took part in the famous Grunwald Battle of July 15, 1410, then most of them settled in Lithuania and served as soldiers organized in troops, called up in need by Lithuanian rulers.