Channel Island repeatedly compared with the Isle of Man in seventeenth- and eighteenth-century constitutional and administrative records.

The comparison was explicit in the Atholl Papers. In discussing a possible Crown purchase of Mann, the Duke of Atholl argued that Crown ownership would not extinguish the inhabitants' rights to their constitution, laws, administration of justice and internal trade. He pointed to the case of “Guernsey Jersey Sark and Alderney”, whose imports and exports remained governed by their own laws.

The Commonwealth records also place Jersey and Mann alongside one another. The Calendar of State Papers for the early 1650s contains extensive material on the surrender of Jersey and its subsequent civil and military jurisdiction, followed by material on the condition and government of the Isle of Man after its surrender in 1651.

Both islands consequently required decisions about garrisons, local jurisdiction and the relationship between existing institutions and the new English republican government.