status. An archbishopric in Mercia would also reinforce the kingdom's independence and free it from ecclesiastical dependence on Canterbury in the kingdom of Kent, which Offa had recently brought under Mercian control. Jænberht supported the Kentish king Egbert II, who was not known as a firm supporter of Offa's; an archbishop at Canterbury who was either indifferent or in active opposition to Offa would be an impediment to Offa's ability to establish overlordship of Kent and other areas of England. By elevating another archbishop, Offa would reduce the political power of the archbishops of Canterbury. Elevation of a bishopric to an archbishopric was not unprecedented; in 735 the papacy had elevated another Anglo-Saxon bishopric to an archbishopric, when Ecgbert became the first Archbishop of York. Council of Chelsea Two different versions of the Anglo-Saxon Chronicle record the proceedings of the council. The Peterborough Manuscript (Version E) of the Chronicle records the council under the year 785, although the events took place in 787, and states that "here there was a contentious synod at Chelsea and Archbishop Jænberht relinquished some part of his bishopric, and Hygeberht was chosen by King Offa, and Ecgfrith consecrated as king." The Canterbury Manuscript (Version F) has the council under 785 also, and describes the council as "a full synod sat at Chelsey" but otherwise relates much the same events. The historian Nicholas Brooks sees the coupling of the elevation of Lichfield with the consecration of Ecgfrith, who was Offa's son, as significant. He argues that Offa desired to have Ecgfrith consecrated as his successor during Offa's lifetime, but was unable to get Jænberht to agree, and this was another factor in the creation of Lichfield as an archbishopric. Hygeberht consecrated Ecgfrith after Hygeberht's elevation to archiepiscopal status. Offa vowed at the council to donate 365 mancuses each year to the papacy, to provide for poor people in Rome and to provide lights for St. Peter's Basilica, stated to be a thanks-offering for his victories. C. J. Godfrey has argued that the donation was really in return for the papal approval of Offa's scheme to elevate the diocese of Lichfield to an archdiocese. Whatever Offa's motivation, historians have generally seen the gift as the beginning of Peter's Pence, an annual "tax" paid to Rome by the English Church. Although it appears that the Council of Chelsea approved Lichfield's elevation to an archdiocese, Hygeberht, who was present,