Blood brother can refer to one of two things: a male related by birth, or two or more men not related by birth who have sworn loyalty to each other. This is in modern times usually done in a ceremony, known as a blood oath, where having each person make a small cut, usually on a finger, hand or the forearm, and then the two cuts are pressed together and bound, the idea being that each person's blood now flows in the other participant's veins. In modern times, some gangs have also been rumored to make blood pacts. The process usually provides a participant with a heightened symbolic sense of attachment with another participant.
Örvar-Oddr's saga contains a notable account of blood brotherhood. The Norwegian warrior Örvar-Oddr felt a desire to test his fighting skills with the renowned Swedish warrior Hjalmar. Thus Örvar-Oddr sailed to Sweden with five ships and met Hjalmar, who had fifteen ships. Hjalmar could not accept such an uneven balance of strength and sent away ten of his own ships so that the forces would be even. The two warriors fought for two days with a lot of blood-letting and poetry, but it was a draw. Finally, they realized that they were equals and decided to become sworn brothers by letting their blood flow under a strand of turf raised by a spear. Then, the strand of turf was put back during oaths and incantations.
In the mythology of northern Europe, Gunther and Högni became the blood brothers of Sigurd when he married their sister Gudrun; in Wagner's Ring Cycle, the same occurs between Gunther and Wagner's version of Sigurd, Siegfried, which is marked by the "Blood Brotherhood Leitmotiv". Additionally, it is briefly stated in Lokasenna that Odin and Loki were once blood brothers.
Among the Scythians, the covenantors would allow their blood to drip into a cup; the blood was subsequently mixed with wine and drunk by both participants. Every man was limited to having at most three blood brotherhoods at any time, lest his loyalties be distrusted; as a consequence, blood brotherhood was highly sought after and often preceded by a lengthy period of affiliation and friendship (Lucian, Toxaris). The Hungarian hajduks had a similar ceremony, though the wine was often replaced with milk so that the blood would be more visible.
In Asian cultures, the act and ceremony of becoming blood brothers is generally seen as a tribal relationship, that is, to bring about alliance between tribes. It was practiced for this reason most notably among the Mongols and early Chinese.
There is some evidence that Native Americans did it to bring about alliance between tribes.
Southeastern Europe and historical Russia
Blood brothers among larger groups was common in ancient Southeastern Europe where, for example, whole companies of soldiers would become one family through the ceremony. It was perhaps most prevalent in the Balkan peninsula during the Ottoman era, as it helped the oppressed people to fight the enemy more effectively; blood brotherhoods were common in what is today Albania, Bosnia and Herzegovina, Bulgaria, Croatia, Greece, Montenegro, Serbia, Republic of Macedonia. Christianity also recognized sworn brotherhood in a ceremony (known as Greek: adelphopoiesis, Slavic: pobratimstvo in the Eastern Orthodox churches; known as Latin: ordo ad fratres faciendum in the Roman Catholic church). The tradition of intertwining arms and drinking wine is also believed to be a representation of becoming blood brothers.
Blood brotherhood, highly ritualized and subjected to a strong code, was a common practice in the Caucasus, especially among the mountaineers. Some relics of this tradition survive to this day.
Famous blood brothers
- Zhang Fei, Guan Yu and Liu Bei. In the historical novel Romance of the Three Kingdoms by Luó Guànzhōng, these three men swore in their famous Oath of the Peach Garden that despite not being born on the same day, their sworn brotherhood would end with them dying on the same day. Histories only mention that the three men were "close like brothers".
- Yesükhei and Toghril. Yesükhei was Genghis Khan's father. Toghril is better known by his Chinese name Wang Khan.
- Temüjin (Genghis Khan) and Jamukha were childhood friends and blood brothers, although Jamukha later betrayed Temüjin and was executed by him.
- Two Norman knights who took part in the Conquest of Britain in 1066, Robert d'Ouilly and Roger d'Ivry, were well known as blood brothers. It was said that they had agreed beforehand to share the profits of this adventure. They both survived Hastings and were granted lands in Oxfordshire and elsewhere, then worked together on various projects such as Wallingford Castle.
- In the Chinese tale Journey to the West, Sun Wukong (the Monkey King) became blood brothers with a bull demon, but later on, this brother relationship was forgotten because of a conflict that occurred involving the bull demon's son that caused other problems for Wukong.
- In Serbian epic poetry, Miloš Obilić was blood brother with Milan Toplica and Ivan Kosančić
- In The Musical Blood Brothers Michael Johnstone and Edward Lyons are Blood Brothers and stand by each other. They don't realize until the day they die that they are twins.
- In the film Mickybo and Me The two main characters become Blood Brothers.
- The characters' Snake Eyes and Storm Shadow within the G.I. Joe franchise are portrayed as "Blood Brothers" as they shared the same master; despite the fact that they are now in fact enemies.
- Steve Jobs and Steve Wozniak were inseparable friends when they first met, and they were until Jobs' death in 2011