This silver penny was minted for the Danish king Cnut (Canute), who conquered England in 1016. Cnut simply took over many forms of Anglo-Saxon government, including a successful coinage. Rather than a single royal mint, coins were produced in towns all over England, so that it was quite easy to get new coins in all areas. This coin was minted in Bath, which was one of a number of small mint towns in the south west, in the former kingdom of Wessex.
The Anglo-Saxons did not have realistic portraits on their coins in the way that we are used to today. Almost all of the busts that appear on Anglo-Saxon coins are fairly crude copies of Roman coin designs. They tended to copy designs of the late third to early fifth centuries, even though their own coins were being produced several hundred years later. This was because kings in Anglo-Saxon times knew the reputation of the power of Roman emperors, and wanted to be as powerful.
There are a few exceptions to this. The first king of England to introduce a more contemporary style of bust was Cnut (AD 1016-35). Cnut conquered England with an army of Vikings, and shortly afterwards became king of Denmark as well. In 1028 he also became king of Norway. Cnut took over the Anglo-Saxon system of coinage, but two of his three English coin types depart from traditional sub-Roman images. His first type shows him in a crown similar to those pictured in Anglo-Saxon manuscripts of the same period. His second type shows him wearing a helmet. This is a typical helmet of the type worn by Anglo-Saxons, Normans and Vikings in the eleventh century. Contrary to the popular myth about Viking helmets, they had no horns.