The siege of Eltville (or battle of Eltville) in May 1349 was the military engagement by which Charles IV secured the throne of the Holy Roman Empire against his rival, Günther of Schwarzburg.
It was the third time a disputed succession in the Empire had been decided by battle.
[2] Charles then led a large army to the Rhine and encamped at Mainz.
[5] Günther apparently ensconced himself in Eltville, which, according to Matthias von Neuenburg, was a fortified town with a castle (oppidum cum castro).
[1][3] The ill Günther died at Frankfurt on 19 June, possibly poisoned during the siege.