In the 7th Century AD, the valley alongside the River Thames, near today’s town of Chertsey, was struck by devastation. The area was inhabitant largely by pagan tribes who showed no respect to Christianity. To punish the insolent tribes, it is believed that God sent a monstrous serpent to ravage the area. The enormous serpent spawned from the depths of the Thames and started to wreak havoc, devouring livestock and causing discontent among the tribes. The tribesmen tried to kill it many times, but every weapon that struck the serpent miraculously bounced off. The fear among the locals was so palpable that the area progressively began to be abandoned. In 666 AD, Eorcenwald, son of the Christian King Eorcenberht of Kent, visited the desolated area. When he learned about the snake, Eorcenwald made a pact with God. He vowed to build a monastery on the blighted land if the serpent were driven away. Miraculously, upon making this vow, the serpent immediately disappeared back into the depths of the Thames, never to be seen again.Keeping his word, Eorcenwald, who later became known as Saint Eorcenwald, built the Chertsey Abbey on the land where the serpent used to dwell. The Abbey became a symbol of the victory of Christianity over Paganism and evil forces. It prospered as a center of learning and spirituality until the Dissolution of the Monasteries by Henry VIII in the 1530s. Despite the physical destruction of the Abbey, the tale of the monstrous serpent and Saint Eorcenwald’s vow continues to be a vital part of the local folklore.