Notably one of the Ingvar runestones, the Sö 179, raised circa 1040 at Gripsholm Castle, commemorates a Varangian loss during an ill-fated raid in Serkland. The other remaining runestones that talk of Serkland are Sö 131, Sö 279, Sö 281, the Tillinge Runestone and probably the lost runestone U 439. For a detailed account of such raids, see Caspian expeditions of the Rus'.