Otto IV., later Emperor Otto IV., was born in 1175/1176 as the son of Henry the Lion and his wife Mathilde of England. Contemporary chroniclers also call him ‘Otto of Braunschweig’ or ‘Otto, the Saxon’. As the third son of the ducal couple, he couldn’t expect much as the majority of his father’s inheritance was due to go to his older brother, Henry. Otto was only going to inherit Haldensleben.
But the life of this Guelph offspring was going to be different. His fate started to change early in his life when his father, Henry the Lion, the mighty Duke of Bavaria and Saxony, fell from grace with Emperor Frederick Barbarossa. Henry lost all his titles and estates and the family went into exile at the English court. The young Otto became the favorite nephew of his uncle, Richard the Lion-Heart. The court of the Platagenets counted as one of the culturally most influential courts in Europe and Otto received a courtly and chivalrous education there. When his father returned to Germany with his family, Otto remained with his English relatives. The childless Richard the Lion-Heart assigned the County of York to him. This was understood to be a preparation for his succession to the throne. But Otto could not prevail. Marriage plans with the Scottish Margaretha also failed. Otto was then enfeoffed with the French County of Poitou that was part of his grandmother's inheritance. With the county Otto inherited the title of Duke of Aquitaine. In France he successfully participated in his uncle's military dispute with the French King.
The next important change in Otto's life came in the year 1198. Under the influence of Richard the Lion-Heart and important merchants from Cologne he was surprisingly voted German-Roman King. However, a few months previously the Staufer Philip of Swabia had already been elected King. For the next 10 years the Staufer and the Guelph bitterly fought for power in the Empire. The Staufer
finally prevailed and Otto's defeat seemed sealed when out of the blue Philip was assassinated by a jealous Wittenbacher. Otto was now generally recognised as the King and was crowned Emperor of the Holy Roman Empire by Pope Innocent III. in the year 1209 in Rome.
But peace didn't last long. Otto's plans for a crusade and for the annexation of the Kingdom of Sicily could not be carried out. After his excommunication by the pope, an opposition of princes was formed that made Fredrick II., nephew of Philip of Swabia and son of Henry VI., rival king. A new fight for power began in the Empire. When Otto got involved in the conflict between his uncle Johann Ohnelang of England and the French King, and both were defeated in the battle of Bouvines in 1214, his power basis was irrevocably shattered. When Frederick II. finally asserted himself, Otto moved back to Braunschweig in 1215 and died politically isolated in Harzburg Castle in the year 1218. In Braunschweig he found his final resting place: In St. Blasii Cathedral Otto is buried next to his father, Henry the Lion and their wives Beatrix and Mathilde.