2017-05-09 16:04:09 UTC
Document SC11/5/1644/11, held at the Orkney Archives, is the marriage agreement, dated 21 February 1644, for Margaret Heart, daughter of David Heart and Jean Mowat, and James Grahame. The NAS catalog description is here: http://catalogue.nrscotland.gov.uk/nrsonlinecatalogue/details.aspx?reference=SC11/5/1644/11
I recently ordered an image of this document from the Orkney Archives.
The contract specifies that James Grahame's part of the agreement is to be done by the "advyse of the said Dauid Heart if he sall be on lyff And failyeing of him throw deceas be the advyse of the said [William] Heart his eldest sone and of Mr John Heart Minister his secund sone or ather of thame."
With this evidence, I think that we can now confidently identify the parents of John Heart as David Heart and Jean Mowat. Jean's mother, Christian Stewart, was a daughter of Earl Robert Stewart of Orkney, and Robert was a son of King James V of Scotland by Euphame Elphinstone.
John Heart, who received his M.A. at St. Andrews in May, 1637, was ordained at Crail on March 22, 1643.
Agnes Heart, daughter of John Heart and Agnes Baxter, married Robert Craighead. Their children include colonial immigrants Thomas Craighead, husband of Margaret Wallace, and Katherine Craighead, wife of William Homes. Thomas and William were both Presbyterian ministers. Thomas and Margaret lived in Freetown, Bristol County, Massachusetts, and then in Pennsylvania. Katherine and William lived in Chilmark, Dukes County, Massachusetts (on Martha's Vineyard) where William was the minister from the fall of 1715 until his death in 1746.
For some of the previous discussion of this topic, see