The county has a long history of human settlement stretching back to the Neolithic era. The Romans conquered Dorset's indigenous Celtic tribe, and during the Early Middle Ages, the Saxons settled the area and made Dorset a shire in the 7th century. The first recorded Viking raid on the British Isles occurred in Dorset during the eighth century, and the Black Death entered England at Melcombe Regis in 1348. Dorset has seen much civil unrest: in the English Civil War, an uprising of vigilantes was crushed by Oliver Cromwell's forces in a pitched battle near Shaftesbury; the doomed Monmouth Rebellion began at Lyme Regis; and a group of farm labourers from Tolpuddle were instrumental in the formation of the trade union movement. During the Second World War, Dorset was heavily involved in the preparations for the invasion of Normandy, and the large harbours of Portland and Poole were two of the main embarkation points. The former was the sailing venue in the 2012 Summer Olympics, and both have clubs or hire venues for sailing, Cornish pilot gig rowing, sea kayaking and powerboating.