roman city wall, london

the north wall of st.alphage's churchyard was part of the wall round london. the base is roman c2, built adjoining the wall of the earlier cripplegate fort of the c2 , topped with the late saxon and c14 city wall, crenelated with diaper pattern brick of 1476-7. just beyond the brick is the original north wall of the first saxon st. alphage's church, which was built onto the wall; the chequerwork kentish rag and flint being c14 decoration .