Treaty of Bonn: The Frankish kings Charles the Simple and Henry the Fowler sign a peace treaty or 'pact of friendship' (amicitia) to recognize their borders along the Rhine.

On 7 November 921, the Treaty of Bonn, the text of which calls itself a "pact of friendship" (amicitia), was signed between Charles III of France and Henry I of Germany in a minimalist ceremony aboard a ship in the middle of the Rhine not far from Bonn. The use of the river, which was the border between their two kingdoms, as a neutral territory had extensive Carolingian precedents and was also used in classical antiquity and in contemporary Anglo-Saxon England.

Charles III, called the Simple or the Straightforward, was the king of West Francia from 898 until 922 and the king of Lotharingia from 911 until 919–923. He was a member of the Carolingian dynasty.

Henry the Fowler was the duke of Saxony from 912 and the king of East Francia from 919 until his death in 936. As the first non-Frankish king of East Francia, he established the Ottonian dynasty of kings and emperors, and he is generally considered to be the founder of the medieval German state, known until then as East Francia. An avid hunter, he obtained the epithet "the Fowler" because he was allegedly fixing his birding nets when messengers arrived to inform him that he was to be king.

A peace treaty is an agreement between two or more hostile parties, usually countries or governments, which formally ends a state of war between the parties. It is different from an armistice, which is an agreement to stop hostilities; a surrender, in which an army agrees to give up arms; or a ceasefire or truce, in which the parties may agree to temporarily or permanently stop fighting.