The
Chronicle reports that in 830, Wiglaf "obtained the kingdom of Mercia again". Wiglaf's return to the throne has generally been taken by historians to indicate the end of Ecgberht's overlordship of Mercia. In particular, historian
Frank Stenton argued that the wording of the
Chronicle makes it probable that Wiglaf recovered the kingdom by force, and that if Ecgberht had given the kingdom to Wiglaf this would have been recorded. A charter of 836 has also been cited as evidence that Wiglaf was acting as an independent ruler at that time; it records a council at
Croft, in
Leicestershire, attended by the
Archbishop of Canterbury and eleven bishops, including some from West Saxon sees. Wiglaf refers to the assembly as "my bishops,
duces, and magistrates", indicating not only a recovery of control over his own territory, but some level of authority over the southern church. It is significant that Wiglaf was still able to call together such a group of notables; the West Saxons, even if they were able to do so, held no such councils. Essex, which had been a Mercian dependency, may have been brought back under Mercian overlordship: a King Sigeric of the East Saxons, described as a
minister of Wiglaf's, witnessed a charter in
Hertfordshire at some point between 829 and 837. London, where Ecgberht apparently lost control of the mint, remained a Mercian town through Wiglaf's second reign and beyond. In East Anglia, King
Æthelstan minted coins, possibly as early as 827, but more likely c. 830 after Ecgberht's influence was reduced with Wiglaf's return to power in Mercia. This demonstration of independence on East Anglia's part is not surprising, as it was probably Æthelstan who was responsible for the defeat and death of both Beornwulf and Ludeca. The lack of detailed information about Mercian and Wessex administration makes other theories hard to evaluate: for example, it has been suggested that the West Saxons had a stable tributary system that contributed to its success, or that Wessex's mixed Saxon and British population, natural frontiers, and capable administrators were key factors. Another proposed explanation for the events of these years is that Wessex's fortunes were to some degree dependent on
Carolingian support. The Rhenish and Frankish commercial networks collapsed at some time in the 820s or 830s, and in addition, a rebellion broke out in February 830 against
Louis the Pious, the first of a series of internal conflicts that lasted through the 830s and beyond. These distractions may have reduced Louis's ability to support Ecgberht. In this view, the withdrawal of Frankish influence would have left East Anglia, Mercia and Wessex to find a balance of power not dependent on outside aid. Wiglaf's recovery was not complete. Ecgberht's influence was certainly reduced after 830, but Mercia never recovered control of the south-east, except possibly for Essex, and East Anglia remained independent. It appears that
Wulfred, the archbishop of Canterbury at the time of Ecgberht's victory, remained loyal to Mercia: his coinage terminates when Ecgberht's Kentish coinage begins; and, since a charter of 838 shows Ecgberht agreeing to return property to the church in Canterbury, it is evident that he had seized property from the church earlier.
Æthelwulf, Ecgberht's son, was king of Kent during his father's reign, and fear of continuing Mercian influence in Kent may have been the reason he gave estates to
Christ Church, Canterbury. ==Coinage and charters==