Historic county on the English side of the Irish Sea, with longstanding ecclesiastical, commercial and family connections to the Isle of Man.

The Cumberland coast lay directly across the sea from Mann. Whitehaven became one of the principal English markets for Manx produce and one of the ports most affected by the eighteenth-century running trade.

Cumberland also entered Manx ecclesiastical landholding. The Barony of the Hough in Maughold, later held by the Christians of Milntown, was described in Manx constitutional material as having formerly belonged to the Priory of St Bees in Cumberland. The barony contained about 420 acres and remained an unusual freehold jurisdiction within the Island.

The Christian family itself developed connections on both sides of the sea, including the branch established at Ewanrigg in Cumberland.

The county's coastline appears repeatedly in the debates over Manx smuggling before Revestment. During parliamentary discussion of the purchase of the Island, the Duke of Atholl attacked a customs memorial which blamed Mann for illicit trade on the surrounding coasts. He drew attention to the Solway Firth and the “flat shores of Cumberland and Lancashire”, asking rhetorically whether he was responsible for their geography as well as for the position of his Island.

Whitehaven merchants had already petitioned government about Manx tobacco and other smuggling, making the Cumberland coast one of the principal points at which the running trade met the British customs system. Their 1752 memorial complained particularly that tobacco manufactured on Mann was being carried clandestinely into Ireland and that the same smuggling fleets interfered with the coal trade from Whitehaven and neighbouring ports to Dublin.