 He was baptized as Gleb and went on to rule Pinsk, Polotsk, and – as his patrimony by invitation of Novgorod's nobles – Ladoga, Oreshek and Korela.He initiated a tradition of Lithuanian mercenary service north of Novgorod on the Swedish border that lasted until Novgorod's fall to Moscow in 1477 and helped keep Moscow at bay.In 1345 Narimantas became the strongest supporter of his deposed brother Jaunutis and went to Jani Beg, Khan of the Golden Horde, to ask for support against Algirdas and Kęstutis.