 This 'heavy coinage' can be closely dated, for no examples of it are known in the name of Archbishop Iænberht, whilst there are no 'light' (i.e., pre-reform) pennies of Archbishop Æthelheard, indicating that the reform took place in 792 or 3.The coins of Offa provide valuable evidence for a new dimension of royal authority and action with regard to the coinage, and have received much attention from historians because of their impressive imagery and range of royal titulature