He could not inherit the title of Earl of Mar due to the Writ of Attainder for treason passed against his father in 1716 for his role in the First Jacobite Rebellion (1715).
[3] Thomas, Lord Erskine, son of John, 6th and 23rd Earl of Mar was initiated in Lodge Kilwinning Scots Arms, Edinburgh, No.3, in 1736.
His name is second on the list of registrations in Grand Lodge made by Kilwinning Scots Arms in 1739.
Lord Erskine, being under the shadow of his father's attainder, and being denied succession to the title of Earl of Mar, led the quiet life of a country gentleman and had more time to devote himself to the study of Freemasonry.
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