Sir Alexander Seton was probably the brother of Sir Christopher. He received considerable grants of land from King Robert Bruce, and was one of the signatories of the letter addressed by the Scottish nobles to the pope to assert the independence of Scotland. He was twice sent on embassies to England, and in 1333 he defended the town of Berwick against the English. He agreed with the English to surrender the town on a certain date unless he received relief before that time, giving his eldest surviving son Thomas as a hostage. On the refusal of the Scots to surrender at the expiry of the term Thomas Seton was hanged in sight of the garrison. This incident is related by Fordun and Boece, but with inconsistencies that have rendered it suspect. An elder son, Alexander, had perished in 1332 in opposing the landing of Edward Baliol; according to some authorities the third son, William, was hanged with his brother, but he is generally said to have been drowned during the siege; his daughter Margaret married Alan de Wintoun.
The tragic death of young Thomas Seton was the subject of a ballad of Seton's Sons, printed in Sheldon's Minstrelsy of the Scottish Border; of a tragedy, The Siege of Berwick (1794, printed 1882) by Edward Jerningham, and of another by James Miller (1824).
Extracted from the entry for SETON (Family) in the 1911 Encyclopedia Britannica, the text of which lies within the public domain.