Harald: I think we should be cautious of assuming a peaceful takeover just because we don't have any evidence for it.

I was struck by the rumored claim: "Mercia seemed to harbor a respect or love of Athelstan. William of Malmesbury in his Gesta Regum Anglorum states that Athelstan was raised in the household of Athelflaed and Athelred of Mercia, two highly respected and loved figures by the Mercian people." (according to Gyrth, citing William of Malmesbury, note 52.)

I would be interested to know the 12th century Anglo-Norman view on English claims to Scotland: and whether or not William of Malmesbury was stating a known fact here, or was merely repeating an oral (politically correct) legend.

If the former is the case, then it seems unnecessary (to my mind) that Athelstan even submit to a coronation as king of Mercia. But if the latter (an oral tradition not based in fact), then Athelstan was possibly pacifying a Mercian traditional independence to avoid trouble to himself. A crowning (again) as king of Mercia would be unwelcome in the mind of a man who sees himself as king of all Britain - with unification of the whole island under his one rule as his goal: having set that precedent in Mercia, would Athelstan (later) have to submit to a crowning as king of Strathclyde and Scotland ? How many little kingdoms would Athelstan then have to be crowned for to keep his disparate people happy and pacified in their illusions of a traditional independence ? Surely, additional crownings would weaken the claims of Athelstan to be the only king of Britain.

So the Mercian coronation has to be evidence (as Harald says) of an uneasy takeover; and not a welcomed "homecoming" of the atheling who had been raised by his aunt Athelflaed the "beloved" queen of Mercia.