Æthelwulf's first Rochester coinage may have begun when he was still sub-king of Kent, under Egbert. A hoard of coins deposited at the beginning of Æthelwulf's reign in about 840, found in the Middle Temple in London, contained 22 coins from Rochester and two from Canterbury of the first issue of each mint. Some numismatists argue that the high proportion of Rochester coins means that the issue must have commenced before Egbert's death, but an alternative explanation is that whoever hoarded the coins simply happened to have access to more Rochester coins. No coins were issued by Æthelwulf's sons during his reign.