Following the Revestment of 1765, the defence of the Isle of Man passed to the British Crown, and drafts from English line regiments were stationed on the Island. The garrison was based primarily at the barracks in Castletown, with soldiers performing duties previously carried out by the Lord's own garrison forces.

Their spiritual provision was an afterthought. Governor Edward Smith wrote to Lord North in October 1783 asking, among other things, for a chapel in Castle Rushen intended for the use of the troops barracked within the Castle, and for a royal portrait to go with it.

The Island's own forces came to matter more than the drafts. The Manx Fencibles and the Volunteers were raised for the French wars, organised in battalions under Lieutenant-Governor Alexander Shaw as Major Commandant with William Cunningham as first Major, and the captains included John Taubman, C. Heywood, Thomas Christian, John Frissell and George Quayle. Major Taubman carried the sword before the Duke of Atholl in the Tynwald procession, and he and the Lieutenant-Governor pressed the Home Office to date the Fencibles' commission from 24 August 1798. A separate corps of Yeomanry Cavalry was raised in 1796 under Thomas Gawne.

The garrison was called on for civil duties too. When a ship was wrecked and the officers of the port judged they could not keep the cargo from being plundered, they applied to the Lieutenant-Governor for a corporal's guard of Fencibles.