Robert IV (1185 – 1218) is of particular note; he earned the title Robert the Justice. King Henry II (1154 – 1189) appointed him Head of the Itinerant (travelling from place to place) justices of England, in effect acting as Lord Chief Justice. In 1215 he deserted King John whilst on campaign in France and sided with the French king. This action had far reaching consequences. By royal command an order was given to punish Robert by seizing all of his lands, imprison his son Geoffrey and to demolish Tamworth Castle:

“Go without delay to the Castle for Tamworth and to hold and retain it. With all
possessions, horses, arms and harnesses, so that he shall throw it down immediately”
December 30th 1215

Physical evidence exists today of the part destruction of the Sandstone castle keep. Shortly after King John’s death peace was made between Robert’s sons and the Crown and they regained possession of their lands.

from: http://minisites.tamworth.gov.uk/castlehome/medieval.aspx