The 1888 boundaries had no bearing on the actual county boundaries; they were only administrative. The same was true in 1974 and at other points in time.

According to archaeologists, Tamworth castle was built in the late eleventh or early twelfth century. It appears to be a typical Norman motte-and-bailey fortress, most likely designed by Robert le Despencer around 1080. No evidence of any Anglo-Saxon structures has been discovered despite multiple excavations in and around the castle, the most recent of which was conducted in February 2024 by Centre of Archaeology of Staffordshire University.