The crowns and lions represent Henry I, whose patronage was essential to the priory at its founding.
The gatehouse was originally built in 1595 by Sir Philip Scudamore. By the turn of the 20th century, it had been tiled over, but after zeppelin damage in World War I it was restored as a memorial to Aston Webb, E. A. Webb and F. L. Dove for their work in the preservation of the church.