"Otto IV (1175 – 19 May 1218) was one of two rival kings of Germany from 1198 on, sole king from 1208 on, and Holy Roman Emperor from 1209 until he was forced to abdicate in 1215. The only German king of the Welf dynasty, he incurred the wrath of Pope Innocent III and was excommunicated in 1210." - (en.wikipedia.org 11.08.2021)
