In the geologic timescale the Bathonian epoch is a stage during the Middle Jurassic, of the Mesozoic era of the Phanerozoic eon. It lasted from approximately 167.7 Ma to around 164.7 Ma (million years ago). The Bathonian age succeeds the Bajocian age and precedes the Callovian age. The stage takes its name from Bath, a spa town in England built on Jurassic limestone.