Colla's marriage to Evelyn MacQuillan, brought a tentative peace between the previous opposing clans.
Attempts were made by Thomas Radclyffe, 3rd Earl of Sussex, Lord Lieutenant of Ireland, to expel the MacDonnells back to Scotland.
[1] In 1551 the castle was besieged by English forces under the command of the Lord Deputy of Ireland, Sir James Croft, in the course of an expedition against the MacDonnell's.
Another siege in 1555 by English forces, the castle was partly destroyed by cannon fire and rebuilt afterwards by Colla.
This was a difficult frontier posting, subject to hostility from the English and risings from the displaced MacQuillin's, and upon offering to the youngest brother Sorley Boy MacDonnell, he accepted.