Mowat was born in Sunnhordland, probably on the Hovland farm at Tysnes which his father had acquired ca. 1590. Mowat was the son of Anders Mowat til Hovland (ca. 1530–1606) and Else Christoffersdatter til Seim (ca. 1550–1622), daughter of Danish-Norwegian Navy officer Kristoffer Throndsen. His father was engaged in trade between Norway and Shetland. Besides Hovland, his father acquired several other farms within the vicinity of Bergen.
