Cumberland County is a county located in Maine. It was incorporated in 1760 and was named after William Duke of Cumberland, son of George II. The county is comprised of three cities and 24 towns, with the city of Portland as the county seat. The area of the county is 853 square miles. The population as of December 2000 was more than 265,000. Cumberland County is headed by three commissioners, each elected from one of the three districts within the county. The county is charged with the responsibility for operating and providing buildings and improvements necessary for county jails, courthouses, register of deeds, register of probate, register of insolvency and clerk of courts.