Celtic people settled in Britain around 700 BC and had women leaders such as Boadicea who fought against the Romans. The Romans occupied most of England and Wales by AD 43 and built Hadrian's Wall along the Scottish border. When the Romans left, the Angles and Saxons attacked Britain and the Celts fled to Wales, Scotland, and Cornwall. In 793, the Vikings attacked the monastery on Lindisfarne, killing the monks and stealing gold and silver. The Vikings then remained in Britain for almost 300 years as they sought new farmland and often raided other peoples for valuable goods. They were skilled sailors who decorated their longships with dragon heads.