The silver penny was almost the only coin used in middle and later Anglo-Saxon England. Æthelwulf's coinage came from a main mint in Canterbury and a secondary one at Rochester; both had been used by Egbert for his own coinage after he gained control of Kent. During Æthelwulf's reign, there were four main phases of the coinage distinguishable at both mints, though they are not exactly parallel and it is uncertain when the transitions took place. The first issue at Canterbury carried a design known as "Saxoniorum", which had been used by Egbert for one of his own issues. This was replaced by a portrait design in about 843, which can be subdivided further; the earliest coins have cruder designs than the later ones. At the Rochester mint the sequence was reversed, with an initial portrait design replaced, also in about 843, by a non-portrait design carrying a cross-and-wedges pattern on the obverse.