In 325 BC, Pytheas of Massalia, a Greek geographer, explored much of the coast of England and Norway and developed the means of determining latitude from the declination of the North Star. His account of tides is also one of the earliest accounts that suggests a relationship between them and the moon. This relationship was later developed by English monk Bede in De Temporum Ratione (The Reckoning of Time) around 700 AD.