 Æthelberht was stopped by Offa of Mercia from minting his own coins , of which only four examples have ever been found . One of these coins , a ' light ' penny , said to have been found in 1908 at Tivoli , near Rome , is similar in type to the coinage of Offa . On one side is the word REX , with an image of Romulus and Remus suckling a wolf : the obverse names both the king and his moneyer , <unk> , who struck coins for both Offa and Coenwulf of Mercia . Andy Hutcheson has suggested that the use of runes on the coin may signify " continuing strong control by local leaders " . According to Marion Archibald , the issuing of " flattering " coins of this type , with the intention to win friends in Rome , probably indicated to Offa that as a sub @-@ king , Æthelberht was assuming " a greater degree of independence than he was prepared to tolerate " . 
