Cavan is a sparsely populated county in north central Ireland, immediately south of the border with Northern Ireland, about midway between the Atlantic Ocean and the Irish Sea. The rural countryside of County Cavan is dotted with lakes and drumlins (small hillocks created by glaciers), and the longest river in Ireland, the 186 mile long River Shannon, originates in the rugged Cuilcagh Mountains in the west of the county.

Small-scale Dairy farming and hog raising are the principal economic activities of the county and oats, potatoes, and flax are the primary crops.

There are a few remaining cairn tombs and crannog islands dating from ancient times in Cavan and Magh Sleacht plain near Ballyconnell was an important Celtic pagan shrine. When Saint Patrick established Christianity in Armagh, he also set up a monastery in Kilnavert in Cavan.

The Normans were not successful in their 12th century invasion of the area, which was ruled by the O'Reilly family. The O'Reillys joined with the other Irish Earls, the O'Neills of Tyrone and the O'Donnell's of Donegal to fight the English invaders, but they were defeated in 1603 and Cavan was planted with English and Scottish settlers.

The Irish Ulster leader Owen Roe O'Neill used Cavan as his base for a rebellion against the English, during which he defeated General Munro at Benburb, but Cromwell retook Cavan in 1649, after O'Neills death. Irish nationalism remained strong in Cavan, however, and like Donegal and Monaghan, although Cavan was part of the historical province of Ulster, it became part of the Republic of Ireland, rather than Northern Ireland, when the island was divided in 1921