It is situated on a hill-top site near entrance to town, where in the past several tracks met. The area began to be settled in the late tenth century: and St Swithun (Bishop of Winchester, 852-862) was the choice for church patron. To this day it remains a visible landmark.
Near the entrance to the church, three stones mark the supposed ashes of Anne Tree, Thomas Dunngate and John Forman who were burned as martyrs on 18 July 1556 because they would not renounce the Protestant faith.
A national appeal for funds raised £516 in 1788. A programme of restoration in 1874 inaugurated the present appearance. A Trust Fund was set up in 1979 to provide funding for restoration. It is independent of the Parochial Church Council.