Canterbury is an historic English cathedral city and UNESCO World Heritage Site, which lies at the heart of the City of Canterbury, a local government district of Kent in South East England. It lies on the River Stour.Originally a Brythonic settlement called *Durou̯ernon (composed of the ancient British roots *duro- "stronghold", *u̯erno- "alder tree"), it was renamed Durovernum Cantiacorum by the Roman conquerors in the 1st century AD. After it became the chief Jutish settlement, it gained its English name Canterbury, itself derived from the Old English Cantwareburh ("Kent people's stronghold"). After the Kingdom of Kent's conversion to Christianity in 597, St Augustine founded an episcopal see in the city and became the first Archbishop of Canterbury, a position that now heads the Church of England and the worldwide Anglican Communion (though the modern-day Province of Canterbury covers the entire south of England). Thomas Becket's murder at Canterbury Cathedral in 1170 led to the cathedral becoming a place of pilgrimage for Christians worldwide. This pilgrimage provided the theme for Geoffrey Chaucer's 14th-century literary classic The Canterbury Tales. The literary heritage continued with the birth of the playwright Christopher Marlowe in the city in the 16th century.