The county of Ulster contains the city of Derry (or Londonderry) and the towns of Coleraine, Limavady, Magherafelt and Portstewart.
Under old Gaelic Ireland, much of Derry was in the old territory of Tirowen. This was the area of the O'Cahans, or O'kanes. Other families associated with this are incude O'Connor, O'donnell, O'Mullan, McCloskey, O'hegarty, O'Corr, McGurk, Mcrory, O'Diamond, McCrilly, McGilligan, O'Derry, and McColgan.
The city of Londonderry was built on the foundation of a monastery in 546 A.D. It was raided by Danish vikings during the ninth to eleventh centuries. During the rebillion of O'Neill and O'Donnell in 1600, Derry was taken by English forces and following the final defeat mnost of the county was confiscated and given to "adventurers" and others for the purpose of planting it with English and Scottish settlers. The O'Cahans were one of the few original families who retained property in the county. When Ulster was divided into counties, Derry for a time, was known as the county of Coleraine.
Among the common names of settlers in the county are Elliott, Campbell, Anderson, Baird, Thompson, McClintock, Hamilton, Browne, Barr, Stewart, Smith, Johnston, Irwin, Morrison, Young and White.
In 1641 the native Irish joined the general rebellion of Irish Catholics but were defeated and dealt with severely. During the Great Famiine, County Derry was not as badly affected as others. The population was 222,000 in 1841 and by 1851 gad fallen only to 192,000. Derry was an important port for emigration at this time and there was great masses of Irish who left thorugh it's port.