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,[2] 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's maternal grandfather had been deprived of much of his lands (the earldom of Strathearn being completely lost to the King of Scots).

[4][7][8] In return Henry pledged to pay a fee of 1000 nobles before St. Martin's Day (11 November), and, when called upon, serve the king on Orkney or elsewhere with 100 fully armed men for 3 months.

Historians have speculated that in 1391 Sinclair and his troops slew Malise Sparre near Scalloway, Tingwall parish, Shetland.

[7] According to Sir Robert Douglas, 6th Baronet, Sinclair had received the honours of the Orders of the Thistle, Saint Michael (Cockle) and the Golden Fleece.

[citation needed] The name "Zichmni" is either totally fictitious, or quite possibly a transliteration error when converting from handwritten materials to type.

[23] One primary criticism of this theory is that if either a Sinclair or a Templar voyage reached the Americas, they did not, unlike Columbus, return with a historical record of their findings.

Knight and Lomas speculate that the Knights Templar discovered under the Temple Mount in Jerusalem a royal archive dating from King Solomon's times that stated that Phoenicians from Tyre voyaged to a westerly continent following a star called "La Merika" named after the Nasoraean Mandaean morning star.

[31] The theory also makes use of the supposed Templar connection to explain the name Nova Scotia ("New Scotland" in Latin).

It is based on the 18th-century tale that some Templars escaped the suppression of their order by fleeing to Scotland during the reign of Robert the Bruce[32] and fought in the Battle of Bannockburn.

[37] Historians Mark Oxbrow, Ian Robertson,[38] Karen Ralls and Louise Yeoman[39] have each made it clear that the Sinclair family had no connection with the mediaeval Knights Templar.

Karen Ralls has shown that among those testifying against the Templars at their 1309 trial were Henry and William Sinclair – an act inconsistent with any alleged support or membership.