Scythian warriors were allowed only three blood brothers at a time
Swearing brotherhood by mixing blood turns up almost everywhere: Viking sagas, Scythian wine cups, Philippine treaty rites, Mongol steppe alliances and Balkan rebel bands. The Scythians even capped it at three such bonds per man, so that nobody's loyalties could be spread too thin, which made each one hard-won.
Norse foster brothers let their blood run as they crawled beneath a strip of turf propped up on spears, a rite described in Gisla saga. In Orvar-Odd's saga the hero fights the Swedish champion Hjalmar to a standstill and then joins him in the same ceremony. Myth reflects the custom too: the poem Lokasenna says Odin and Loki once mixed blood, which some read as the reason the other gods put up with Loki at all, and Wagner gave the bond its own musical motif in Gotterdammerung.
Scythian partners dripped blood into wine and drank it together, and gold ornaments from the 4th century BC showing two warriors sharing one drinking horn have been linked to that oath. Hungarian hajduks used milk instead so the blood showed clearly, and in the 9th century the chiefs of seven Hungarian tribes sealed their alliance with blood before choosing Almos as leader. On the steppe, sworn brothers were called anda: Genghis Khan's father had one, and Genghis himself swore the bond with his childhood friend Jamukha, who later turned against him.
The bond often doubled as diplomacy. Visayan communities in the Philippines practised sandugo, one blood, mixing drops into a shared cup to seal treaties, as early Spanish and Portuguese visitors recorded. The British colonial official Lord Lugard became blood brother to many African chiefs as deliberate policy, and in the 18th century envoys of George III reportedly exchanged blood with Jamaican Maroon leaders during peace talks. Two Norman knights who fought at Hastings in 1066 were blood brothers who had agreed in advance to split their winnings, and later built Wallingford Castle together.
Churches formalised sworn brotherhood with their own ceremonies, and in the Ottoman-era Balkans whole companies of fighters bound themselves this way. China's Romance of the Three Kingdoms made the Oath of the Peach Garden famous, sealed with a black ox and a white horse, though actual histories say only that the three men were close like brothers.
Source: Blood brother
