John Stewart of Bonkyll
Sir John Stewart of Bonkyll (died 22 July 1298) was a son of Alexander Stewart, 4th High Steward of Scotland. He was a military commander during the First Scottish War of Independence and during the Battle of Falkirk, he commanded the Scottish archers, and was killed during the battle. Stewart is interred in the churchyard of the Falkirk Old Parish Church.
He is the direct paternal ancestor of Henry Stuart, Lord Darnley, the second husband of his brother's descendant, Mary, Queen of Scots. Thus, he is a direct agnatic ancestor of James VI of Scotland, who later became James I of England in 1603. This accession of James I united the thrones of England, Scotland, and Ireland.
John married Margaret de Bonkyl (Bonkill), the heiress daughter of Sir Alexander de Bonkyl of that Ilk, so placed "on a bend Sable three buckles Or" for difference upon the coat of arms of his paternal line, "Or a bend chequey Argent and Azure". They had issue:
Lady Margaret appears to have remarried, as she is named as wife to Sir David de Brechin in 1304.
In a study released in February 2014 Sir John was identified to be the ancestor of all men with the Y chromosome SNP mutation S781, the defining mutation for the Y-DNA haplogroup R1b1a2a1a2c1i1a1.
...
Wikipedia