In Cromwell's time the then Earl of Eglinton dispatched his wife with a garrison of forty men at arms to this fortlet castle for her safe keeping; the defences were strengthened at this juncture.

The Earl was taken prisoner after fighting against Cromwell at the Battle of Worcester (3 September 1651) and Lady Montgomerie was advised by the Marquis of Argyll to either offer the castle to the authorities or have it demolished once the munitions and cannons had been safely removed.

[17] Archibald Hamilton was a friend and correspondent of Oliver Cromwell and was imprisoned in the dungeon at Little Cumbrae castle by the 6th Earl of Eglinton (died 1661) before being taken to Stirling where he was hanged.

[2] The old Statistical Account indicates that this fortlet was taken by surprise and destroyed by Cromwellian forces, possibly in revenge for the role the castle played in the fate of Archibald Hamilton;[2] after this it does not appear to have been restored or tenanted.

In 1651 Charles II permitted: It is our pleasure the number of fortie men which the Lord Montgomerie hath raised and doeth maintaine in at the Isle of Comrie, may be allowed to him in this new levie for so many out of his owne or his fathers proper lands.

[18] In 1609 Robert Hunter was the subject of a complaint to the Privy Council made by the Captain of Dumbarton Castle for going to Little Cumbrae and taking all of the hawks away.

[19] No contemporary Anglo-Saxon or Celtic word for rabbit therefore exists and no mention is made of them in the Domesday Book of 1086, also 'conyngis' (Scots) or 'coneys' was originally the name used for adults and the term 'rabbits' was only applied to the young.

The 6th Earl was a very keen huntsman and estate correspondence shows that he may have introduced deer from Ireland to Little Cumbrae in order to improve the stock.