London suffered severely from Viking attacks and was several times occupied by Viking armies. In 886 Alfred took possession of London, and according to Asser he "restored" the city and "made it habitable again". He then handed control to Æthelred. Historians, however, disagree about the circumstances. According to Frank Stenton, Alfred recovered London by force from the Vikings and handed it to Æthelred because it had previously been a Mercian town, and he respected the traditions of other kingdoms. Marios Costambeys takes a similar view, arguing that Alfred's decision was probably due to the need to maintain unity among the English who were outside Viking territory. Alfred P. Smyth suggests that the "Chronicle's" account reflects bias in Alfred's favour, and that Æthelred took charge because he had a greater role in London's recovery than the West Saxon chronicler was willing to admit. Some versions of the "Chronicle" state that Alfred besieged London in 883, and Simon Keynes argues that Alfred probably took London at that time and that the "occupation" in 886 may have been a restoration of London's defences following Viking attacks close to the city in 885.