Alfred the Great (AD 871-99) was king of Wessex, an Anglo-Saxon kingdom in the far south of England. Although London was not part of this region, one of his coin types has a monogram of the name LVNDONIA. These coins have traditionally been linked with a reference in The Anglo-Saxon Chronicle to Alfred 'restoring' London in 886. This has been taken to mean that Alfred captured London from the Vikings that year, and celebrated his conquest with a new coinage.
However, we know that throughout the mid- to late 870s London was in the hands of Alfred's ally Ceolwulf, king of Mercia. Ceolwulf reigned from 874 to around 879, but no records survive exactly how and when his reign came to an end. After Ceolwulf’s death, Alfred took control of Mercia as well as Wessex, an important step in the creation of a single kingdom of England.
Alfred and Ceolwulf had issued a joint coinage throughout Ceolwulf's reign. Each ruler issued coins in his own name, but with the same designs and weights, and some moneyers issuing coins for both kings. Coins were produced for both kings in London during this period. Alfred's London monogram coinage immediately followed this, suggesting that Alfred took complete control of London long before 886. According to one theory, Alfred gained London as part of a treaty following his victory in battle over the Vikings in 878. Another theory suggests that it was around 880, following the death or deposition of Ceolwulf.
Either way, the coins have nothing to do with Alfred's 'restoration' of London in 886. By then, London had been in Alfred's hands for several years. The 'restoration' is more likely to refer to repairs to damage done during a Viking raid of 885 than any new conquest by Alfred.