Not far from the Bridport to Dorchester Roman road is Compton Valence and this was where Dorchester obtains its water supply.
The church dedicated to St Thomas was rebuilt in 1838 by the Williams family, at the same time as the nave was made longer and a north aisle was added but today all that remains of the original 15th century church is the tower. .

The rebuilding was done by using Portland or Ham stone Bath stone was used to construct the pulpit and the alter was originally Caen stone.