David Sinclair of Alterwall

"Douglas gives the Master a legitimate son David, but this is an error. In August 1587 David Sinclair obtained a charter of Alterwall from Henry Keir of Greenland; and in a Crown charter which followed thereon he is designated "filio naturali quond. Joannis Magistri Cathanensis". In 1588 he obtained Letters of Legitimation. He had two sons, John, killed at Thurso in 1612, and Colonel George, who perished in the same year in the luckless expedition to Norway, of which full details are to be found in Calder's History of Caithness and elsewhere." John Henderson, Caithness Family History (1884).