Achill Island (; ) in County Mayo is the largest of the Irish isles, and is situated off the west coast of Ireland. It has a population of 2,594. Its area is . Achill is attached to the mainland by Michael Davitt Bridge, between the villages of Achill Sound and Polranny. A bridge was first completed here in 1887. Other centres of population include the villages of Keel, Dooagh, Dooega, Dooniver, and Dugort. The parish's main Gaelic football pitch and secondary school are on the mainland at Polranny. Early human settlements are believed to have been established on Achill around 3000 BC. The island is 87% peat bog. The parish of Achill consists of Achill Island, Achillbeg, Inishbiggle and the Corraun Peninsula. Roughly half of the island, including the villages of Achill Sound and Bunacurry are in the Gaeltacht (traditional Irish-speaking region) of Ireland, although the vast majority of the island's population speaks English as their daily language. History It is believed that at the end of the Neolithic Period (around 4000 BC), Achill had a population of 500–1,000 people. The island would have been mostly forest until the Neolithic people began crop cultivation. Settlement increased during the Iron Age, and the dispersal of small promontory forts around the coast indicate the warlike nature of the times. Megalithic tombs and forts can be seen at Slievemore, along the Atlantic Drive and on Achillbeg. Overlords Achill Island lies in the Barony of Burrishoole, in the territory of ancient Umhall (Umhall Uactarach and Umhall Ioctarach), that originally encompassed an area extending from the County Galway/Mayo border to Achill Head. The hereditary chieftains of Umhall were the O'Malleys, recorded in the area in 814 AD when they successfully repelled an onslaught by the Vikings in Clew Bay. The Anglo-Norman invasion of Connacht in 1235 AD saw the territory of Umhall taken over by the Butlers and later by the de Burgos. The Butler Lordship of Burrishoole continued into the late 14th century when Thomas le Botiller was recorded as being in possession of Akkyll and Owyll. Immigration In the 17th and 18th centuries, there was much migration to Achill from other parts of Ireland, particularly Ulster, due to the political and religious turmoil of the time. For a while, there were two different dialects of Irish being spoken on Achill. This led to many townlands being recorded as having two names during the