At the time of Fundin's birth, Thrór'sKingdom under the Mountain had been established for seventy-two years, and given his descent from the House of Durin, it seems extremely likely that he spent most of his life in the Dwarf-kingdom beneath the Lonely Mountain. Smaug descended on Erebor in III 2770, when Fundin would have been 108 years old, and after that point he must have gone into exile with KingThrór and the rest of his people.