Henry Sinclair, Earl of Orkney

Henry I Sinclair, Jarl of Orkney, Baron of Roslin (c.1345 – c.1400) was a Scottish and a Norwegian nobleman. Sinclair held the title Earl of Orkney (which refers to Norðreyjar rather than just the islands of Orkney) under the King of Norway. He is sometimes identified by another spelling of his surname, St. Clair. He was the grandfather of William Sinclair, 1st Earl of Caithness, the builder of Rosslyn Chapel. He is best known today because of a modern legend that he took part in explorations of Greenland and North America almost 100 years before Christopher Columbus. William Thomson, in his book The New History of Orkney, wrote: "It has been Earl Henry's singular fate to enjoy an ever-expanding posthumous reputation which has very little to do with anything he achieved in his lifetime."

Henry Sinclair was the son and heir of William Sinclair, Lord of Roslin, and his wife Isabella (Isobel) of Strathearn. She was a daughter of Maol Ísa, Jarl of Orkney. Henry Sinclair's maternal grandfather had been deprived of much of his lands (the earldom of Strathearn being completely lost to the King of Scots).

Sometime after 13 September 1358, Henry's father died, at which point Henry Sinclair succeeded as Baron of Roslin, Pentland and Cousland, a group of minor properties in Lothian.

Although the Norwegian jarldom of Orkney was not an inheritable position, successive appointments had operated as if it had been. After a vacancy lasting 18 years, three cousins – Alexander de L'Arde, Lord of Caithness; Malise Sparre, Lord of Skaldale; and Henry Sinclair – were rivals for the succession. Initially trialling de L'Arde as Captain of Orkney, King Haakon VI of Norway was quickly disappointed in de L'Arde's behaviour, and sacked him.

...
Wikipedia