For 10 points, name this Frankish king who was crowned Holy Roman Emperor in 800.
This ruler signed the Treaty of Heiligen with the Danish king Hemming. This leader defeated the Lombards in the Siege of Pavia. Scholars such as Alcuin of York engineered this man's namesake renaissance. This ruler lost the Battle of Roncevaux (ron-say-VOE) Pass, where his rearguard was led by Roland (roe-LON). He was the son of (*) Pepin the Short and the grandson of Charles Martel. For 10 points, name this Frankish king who was crowned Holy Roman Emperor in 800.
This ruler signed the Treaty of Heiligen with the Danish king Hemming.
{Charlemagne} [or Charles the {Great}; or Charles le {Grand}; or {Carolus Magnus}; or {Karl der}