 The Archbishop of Canterbury is the primate of the Church of England and the worldwide Anglican Communion owing to the importance of St Augustine , who served as the apostle to the pagan Kingdom of Kent around the turn of the 7th century . The city 's cathedral became a major focus of pilgrimage following the 1170 martyrdom of Thomas Becket . A journey of pilgrims to his shrine served as the frame for Geoffrey Chaucer 's 14th century classic The Canterbury Tales . 
