Editing Coenwulf of Mercia (section)

==Background and sources==
For most of the 8th century, Mercia was dominant among the Anglo-Saxon kingdoms south of the river Humber. [[Æthelbald of Mercia|Æthelbald]], who came to the throne in 716, had established himself as the overlord of the southern Anglo-Saxons by 731.<ref name=BEASE_306>Simon Keynes, "Mercia", in Lapidge et al., ''Blackwell Encyclopaedia of Anglo-Saxon England'', p.&nbsp;306.</ref> He was assassinated in 757, and was briefly succeeded by [[Beornred of Mercia|Beornred]], but within a year [[Offa of Mercia|Offa]] ousted Beornred and took the throne for himself. Offa's daughter [[Eadburh]] married [[Beorhtric of Wessex]] in 789, and Beorhtric became an ally thereafter.<ref name=Stenton_210>Stenton, ''Anglo-Saxon England'', p.&nbsp;210.</ref> In Kent, Offa intervened decisively in the 780s,<ref name=Kirby_167>Kirby, ''Earliest English Kings'', p.&nbsp;167.</ref> and at some point became the overlord of [[Kingdom of East Anglia|East Anglia]], whose king, [[Æthelred I of East Anglia|Æthelred]], was beheaded on Offa's orders in 794.<ref name=Yorke_64>Yorke, ''Kings and Kingdoms'', p.&nbsp;64.</ref>

Offa appears to have moved to eliminate dynastic rivals to the succession of his son, [[Ecgfrith of Mercia|Ecgfrith]].<ref name = Yorke_118/> According to a contemporary letter from [[Alcuin of York]], an English deacon and scholar who spent over a decade as a chief advisor at [[Charlemagne]]'s court,<ref name=BEASE_24>Lapidge, "Alcuin of York", in Lapidge et al., "Encyclopaedia of Anglo-Saxon England", p.&nbsp;24.</ref> "the vengeance of the blood shed by the father has reached the son"; Alcuin added, "This was not a strengthening of the kingdom, but its ruin."<ref name=EHD_786>Letter of Alcuin to Mercian ealdorman Osbert, tr. in Whitelock, ''English Historical Documents'', p.&nbsp;787</ref> Offa died in July 796. Ecgfrith succeeded him but reigned for less than five months before Coenwulf came to the throne.<ref name=BEASE_111>Simon Keynes, "Coenwulf", in Lapidge et al., ''Blackwell Encyclopaedia of Anglo-Saxon England'', p.&nbsp;111.</ref>

A significant corpus of letters dates from the period, especially from Alcuin, who corresponded with kings, nobles, and ecclesiastics throughout England.<ref name=BEASE_24/> Letters between Coenwulf and the papacy also survive.<ref>See the exchange of letters between Coenwulf and [[Pope Leo III]] in Whitelock, ''English Historical Documents'', 204 and 205, pp.&nbsp;791–794.</ref> Another key source for the period is the ''[[Anglo-Saxon Chronicle]]'', a collection of annals in [[Old English]] narrating the history of the Anglo-Saxons. The ''Chronicle'' was a [[Wessex|West Saxon]] production, however, and is sometimes thought to be biased in favour of Wessex.<ref name=CampbellTASS_144>Campbell, ''Anglo-Saxon State'', p.&nbsp;144.</ref> [[Anglo-Saxon Charters|Charters]] dating from Coenwulf's reign have survived; these were documents granting land to followers or to churchmen and were witnessed by the kings who had the authority to grant the land.<ref name=BlairRBaEE_14>Hunter Blair, ''Roman Britain'', pp. 14–15.</ref><ref name=Campbell_95_2>Campbell, ''The Anglo-Saxons'', pp. 95–98.</ref> A charter might record the names of both a subject king and his overlord on the witness list appended to the grant. Such a witness list can be seen on the [[Ismere Diploma]], for example, where Æthelric, son of king [[Oshere]] of the [[Hwicce]], is described as a "''subregulus''", or subking, of Æthelbald.<ref name=EHD_453>Whitelock, ''English Historical Documents'', 67, pp.&nbsp;453–454.</ref>