Alexander Seton, 3rd Earl of Dunfermline (12 June 1642 – btw.
He succeeded his father, Charles Seton, 2nd Earl of Dunfermline, in 1672.
Alexander was a younger son, but his older brother Charles had predeceased his father shortly before, in a naval battle of the Third Anglo-Dutch War.
He had no children, and upon his death in 1677 the title went to his brother, James Seton, 4th Earl of Dunfermline.
[1] The title became extinct with James, who was outlawed in 1690 after fighting in the Battle of Killiecrankie, and died without heirs in 1694.