In the sixteenth century Mongevlin was the chief residence of Iníon Dubh, who was the daughter of James MacDonald, 6th of Dunnyveg, and mother of Red Hugh O'Donnell.

Three miles above Cargan stands a fort called McGevyvelin (Mongivlin) upon the river of Lough Foyle O'Donnell's mother's chief house."

When Ineen Dubh came to Ireland to marry Aodh mac Maghnusa Ó Domhnaill (Anglicized: Sir Hugh O'Donnell), she brought a force of 100 of the biggest men she could find in Scotland.

[citation needed] In April 1608, following the Flight of the Earls (14 September 1607), Sir Cahir O’Doherty, the last Gaelic Lord of Inishowen and the rebel leader, laid siege to the City of Derry.

Niall Garve, being greedy, wanted to be close to the action and have a chance of getting a good share of the spoils when Derry would be sacked.

[citation needed] The present ruin was built for Sir John Stewart of Methven, an illegitimate son of the 2nd Duke of Lennox, a senior-ranking Scottish nobleman, who was also governor of Dumbarton Castle until he was convicted of cruelty and adultery.