Charles was one of my grandmother's ancestors. He and his brothers immigrated to the U.S. in 1746. I have pieced together his background (successively) as:
William Glendenin (1680 - 1764)
William Glendenin (before 1614 - ?)
Alexander Glendening of Parton (abt 1563 - 1616)
John Glendening of Parton (1510 - 1560)

Oops! If these dates are correct Alexander cannot be a son of John. Also, a record of the Glendonwyn Baronet indicates that son William died young - it does not say how young and whether before or after marriage. From what I have right now it would appear that there must be at least one missing generation between William and Alexander.

Now, from what I have found to date, John ties back to Scottish Royalty - the Stewart line and Robert the Bruce. So far I have not had a chance to investigate his mother's tie, but supposedly his grandfather, Sir Simon of Glendonwyn and Parton, married Lady Mary Douglas, daughter of Archibald, fourth Earl of Douglas, and Princess Margaret Stewart. To date, however, I have found no evidence that Archibald and Margaret had a daughter named Mary.

The Question: Has anyone found proof of these connections, or has someone found some names and made connections to generate a non-existent connection to old world royalty?