May 11, 973. Edgar's (second) consecration, at Bath
Edgar's consecration at Bath at Pentecost in 973 is reported in a poem in the Anglo-Saxon Chronicle and described at some length in Byrhtferth's Life of St Oswald. He was probably consecrated shortly after his accession (see entry on 959), which would make this his second consecration.
It may be that Edgar was laying claim to a larger realm, or a larger vision of his realm, than his predecessors, just as one of the reasons for Edward the Elder's foundation of the New Minster in 901 may have been a desire to give tangible expression to his kingdom of the Anglo-Saxons. It is worth noting that Edgar's consecration took place at Bath, not Kingston-upon-Thames, which was the site for most of the known royal consecrations in the 10th century (see Keynes, pp.270-1). Kingston was an old West Saxon royal estate in Surrey, while Bath was not only an Alfredian burh (fortress) on the Mercian / West Saxon border, but a town whose impressive Roman remains were still visible in the 10th century (see Nelson, p.301), and may have conjured up images of old Roman Britannia.
Certainly other events of the year involve conspicuous displays of royal power and unity over the whole country. Two manuscripts of the Chronicle note that after the consecration at Bath the king took his whole naval force to Chester, where six kings met him and pledged to be his allies on sea and on land. Ælfric in his nearly-contemporary Life of St Swithun says there were eight kings, Cumbrians and Scots (extract at EHD 239(g)), and John of Worcester in the 12th century names them as Kenneth of Scotland, Malcolm of Cumbria, Maccus of the Isles, and five others, Dufnal, Siferth, Hywel, Iacob, and Iuchil, and adds the detail that the eight kings rowed him along the river Dee, while Edgar held the rudder. It was likely in the same year (q.v.) that a reform of the coinage removed the regional variation that had existed and standardized Edgar's coinage across the whole kingdom. (See further Nelson, pp.302-3.)
That a real change had occurred between the 950s and 973 that might justify such a ceremony is suggested by the fact that in 975, as also in the 950s, there were two princes who seemed to expect to inherit the kingship, but there was no question in 975 of dividing the kingdom. The partition of the kingdom in 1016 was the result of English defeat in battle after over three decades of Viking raids, and is more analogous to the Vikings sharing out Mercia with Coenwulf in 877 than a partition between rival princes on the same side; in 1035, when there were two claimants to the throne on a more equal footing, there was again no question of division.
S. Keynes, The Diplomas of King Æthelred "The Unready" 978-1016: A Study in their Use as Historical Evidence (Cambridge: 1980)
J. Nelson, "Inauguration Rituals", Politics and Ritual in Early Medieval Europe (London: 1986), pp.283-307