Holy Roman Emperor Otto IV

Holy Roman Emperor Otto IV
c. 1175 – May 19, 1218

Holy Roman Emperor Otto IV was born around 1175 into the German Welf dynasty. His father, Henry, was the Duke of Saxony and Brunswick, while his mother, Matilda, was King Henry II of England’s eldest daughter. At the time of Otto’s birth, Duke Henry had been at the height of his power. However, his arrogance caused his fellow Saxon nobles to turn against him. After hearing charges against Henry, Holy Roman Emperor Frederick I took control of the duke’s lands and divided them. In turn, Henry and his family lived as exiles at the English court for several years.

After Frederick I’s death during the Third Crusade in 1190, Henry and Matilda returned to Germany. Due to his unstable situation, the duke opted to leave his son in England. After Henry II’s passing in 1189, Otto’s uncle, Richard I, oversaw his upbringing. In 1196, the king granted his nephew the titles of the count of Poitou and the duke of Aquitaine. After Richard’s death on April 6, 1199, the newly crowned King John continued supporting Otto. During his time in England, Henry died on August 6, 1195.

German King

On September 28, 1197, Holy Roman Emperor Henry VI died. The emperor’s heir, Frederick, was only a toddler, causing the German nobility to look elsewhere for a successor. Initially, the nobility elected the emperor’s younger brother, Philip of Swabia, as German king in March 1198. However, those opposed to the Hohenstaufens instead elected Otto in June 1198. With neither side backing down, civil war soon erupted.

In 1201, Otto obtained Pope Innocent III’s backing. In return, Otto agreed to give the pope his territory in central Italy. Despite this success, Otto began to lose support. In 1204, Archbishop Adolf of Cologne, initially one of Otto’s most prominent supporters, changed his allegiance to Philip. By early 1208, Otto had lost so much support that even Innocent joined Philip’s side. Although Otto’s defeat seemed inevitable, his fortune soon changed.

Pope Innocent III
Pope Innocent III

In June 1208, a German noble killed Philip after he objected to a marriage between his daughter and the noble. With their leader dead, Philip’s supporters soon began flocking to Otto. After Otto won the election in November, the new king secured his position by marrying Philip’s daughter, Beatrix. After agreeing again to the pope’s terms, Otto once more gained Innocent’s support. However, the two men’s relationship would quickly sour.

Holy Roman Emperor

In August 1209, the king and pope met in Viterbo, Italy, to discuss their agreement. Instead of fulfilling his promise, Otto decided to back out. The king agreed to respect Sicily’s independence as a counteroffer since Innocent III wanted Frederick as his vassal. Satisfied with the meeting’s outcome, the pope crowned Otto as Holy Roman Emperor in Rome on October 4. As a result, the Welf dynasty replaced the Hohenstaufens on the imperial throne.

Despite swearing not to invade Sicily, Otto IV quickly broke his promise. The emperor and the imperial army attacked Sicily and began conquering southern Italy. In response to his betrayal, Innocent III excommunicated the emperor in November 1210. Unfazed by the act, Otto continued his military campaign before returning to Germany in March 1212. However, the emperor’s position would be compromised after the death of his wife, Beatrix, and the loss of Hohenstaufen support.

In Italy, Frederick had grown from a toddler to a man in his mid-20s. Unlike years prior, Henry VI’s son now posed a threat to Emperor Otto IV. Sensing an opportunity to overthrow the emperor, a group of German nobles began supporting Frederick. In September 1212, Frederick himself started pressing his claim, and a civil war began. Frederick gained the support of France, while Otto had England’s backing. To weaken his rival, the emperor planned a French invasion with King John of England.


Both Holy Roman Emperor Otto IV and John had a lot riding on their invasion. For Otto, his success would secure his throne against Frederick. For John, his victory against Philip II of France would secure his Angevin Empire. Their plan involved Imperial forces attacking France from the north, while English troops attacked from the west. After overwhelming the French, both armies would meet in Paris. On July 2, 1214, Philip and his men defeated John at La Roche-aux-Moines, foiling Otto’s plan.

Philip II of France
Philip II of France

On July 27, 1214, Philip II’s army met Emperor Otto IV’s on a marshy plan between Bouvines and Tournai. The French king had a well-trained force of 15,000 under his command and stationed them on strategic ground. Unlike Philip, the emperor had 25,000 men but were less organized due to having multiple commanders. When the Battle of Bouvines began, Imperial soldiers recklessly rushed at the French without waiting for backup. Although outnumbered, the French’s superior position allowed them to endure countless assaults.

After waiting for an opportunity to strike, Philip II ordered a cavalry charge. The charge proved fatal as the French routed the Imperials, causing Emperor Otto IV and his men to flee. In response to the emperor’s disastrous defeat, Otto lost his remaining supporters to Frederick. The following year, he would be deposed as German king, losing the imperial throne in the process. By the time he died on May 19, 1218, the former emperor’s power had been reduced to only his Brunswick lands.


Holy Roman Emperor Otto IV had a very unstable reign. Due to his unpopularity, the emperor never enjoyed consistent support. Otto’s supporters readily shifted their loyalty when it suited them. By the Battle of Bouvines, Otto’s control of the throne hung by a thread. The emperor’s enemies actively sought to replace him with his rival, Frederick. His devastating loss caused the emperor to finally lose his remaining support and die a humiliated duke.


Dougherty, M. J. (2018). Crusaders, Persecutors and Religious Reformers. In Kings & Queens of the Medieval World: From Conquerors and Exiles to Madmen and Saints (pp. 76-78). London: Amber Books.

The Holy Roman Empire: A Captivating Guide to the Union of Smaller Kingdoms that Started During the Early Middle Ages and Dissolved During the Napleonic Wars. (2019).

Encyclopædia Britannica, inc. (n.d.). Otto IV. Encyclopædia Britannica. Retrieved October 12, 2021, from https://www.britannica.com/biography/Otto-IV.


Andy Tree

I'm a European history enthusiast who seeks to share his passion with others. I hope to inform and inspire readers with my posts!

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