Monaghan formed part of the ancient territory of Oriel, and was known as the MacMahon country because of the dominance of that powerful clan. The name derives from a diminutive plural form of the Irish word muine meaning "brake" (a thickly overgrown area) or sometimes "hillock". The county council's preferred interpretation is "land of the little hills", a reference to the numerous drumlins in the area. From the 13th to the 16th century the MacMahon family controlled Monaghan, but in 1589 control passed to the British crown. Monaghan is in the traditional province of Ulster in northeastern Ireland bordered on the northwest, north, and northeast by Northern Ireland and on the southeast, south, and southwest by counties Louth, Meath, and Cavan. The county covers 1,290 sq km (498 sq mi).