On anthroponymic grounds, Ceolwulf is thought to belong to the C dynasty of Mercian kings, a family which claimed descent from Pybba of Mercia. The C dynasty, beginning with Coenwulf, may have had ties to the ruling family of Hwicce in south-west Mercia. Ceolwulf's immediate ancestry is unknown, but he is thought to be a descendant of Ceolwulf I through his daughter Ælfflæd. Ælfflæd was first married to Wigmund, son of King Wiglaf, and then to Beorhtfrith, son of King Beorhtwulf. Far from being "an unwise king's thane", it is clear that Ceolwulf was a descendant of previous kings. A number of thegns who witnessed charters under Burgred witnessed charters under Ceolwulf, and his charters were witnessed by Mercian bishops, testifying to his acceptance in Mercia.
Mercia, Wessex and the Vikings
The Anglo-Saxon Chronicle offers the following account of Ceolwulf:
This year went the army from the Kingdom of Lindsey to Repton, and there took up their winter-quarters, drove the king , Burgred, over sea, when he had reigned about two and twenty winters, and subdued all that land. He then went to Rome, and there remained to the end of his life. And his body lies in the church of Sancta Maria, in the school of the English nation. And the same year they gave Ceolwulf, an unwise king's thane, the Mercian kingdom to hold; and he swore oaths to them, and gave hostages, that it should be ready for them on whatever day they would have it; and he would be ready with himself, and with all those that would remain with him, at the service of the army.
The Chronicle was compiled on the orders of Alfred the Great, brother-in-law of King Burgred. This account is considered to be biased and politically motivated, written with a view of strengthening the claims of Alfred and Edward the Elder to the overlordship of Mercia, evidenced by a 2015 find of Anglo-Saxon Imperial coins dated to around 879 CE, near Leominster, presumed to have been buried by retreating Vikings. The coins depict both Ceolwulf as a king as well as Alfred, leading some experts to indicate that the two were equals. According to Gareth Williams of the British Museum, "these coins enable us to re-interpret our history at a key moment in the creation of England as a single kingdom." A report by The Guardian adds an additional perspective, suggesting that the coins "rewrite Anglo-Saxon history":
"The presence of both kings on the two emperor coins suggests some sort of pact between the pair. But the rarity of the coins also suggests that Alfred quickly dropped his ally, who was just about written out of history".
Ceolwulf's kingdom is presumed to have been reduced to the northern and western parts of Mercia.
Wales
In 878, King Rhodri Mawr of Gwynedd was killed in battle against the English. As Alfred was then occupied fighting the Vikings, and Mercia traditionally claimed hegemony over Wales, the English leader was probably Ceolwulf. In 881 Rhodri's sons defeated the Mercians at the Battle of the Conwy, a victory described in Welsh annals as "revenge of God for Rhodri". The Mercian leader was Edryd Long-Hair, almost certainly Ceolwulf's successor as Mercian ruler, Æthelred.
Coinage and London
Three types of penny have been found which were issued in Ceolwulf's name. The bulk of them were minted at London and of the type designated as Cross-and-Lozenge, which was also in use by King Alfred of Wessex. Ceolwulf's coinage appears to be closely related to that of Alfred of Wessex, and it has been suggested on this basis that the two kings co-operated against the Vikings. Simon Keynes and the numismatist Mark Blackburn initially suggested that in about 875, Alfred was the sole recognised ruler in London, while Ceolwulf's involvement would have come about only towards the end of his reign, 879. However, in 1998, the same year that their discussion was published, another Cross-and-Lozenge penny struck in Ceolwulf's name came to light, which appears to be contemporary with Alfred's earliest coinage. In October 2015, the Watlington Hoard of coins, jewellery and silver ingots was found near Watlington, Oxfordshire. The find, dating back to the 870s, included coins carrying the image of two Roman emperors accompanied by the name of either Alfred or Ceolwulf.
