The Thirty Comrades (Burmese: ရဲဘော်သုံးကျိပ်) constituted the embryo of the modern Burmese army called the Burma Independence Army (BIA) which was formed to fight for independence from Britain. This was accomplished just before the majority of the Thirty Comrades returned with the invading Japanese Army initially through Southern Burma in December 1941.
In April 1941, small groups of Burmese youth left Burma secretly to obtain military training to fight the British colonists in the struggle for independence. Their leader was Thakin Aung San and they were sent by the Dobama Asiayone ("We Burmans Association") with the intention to get assistance from Guangzhou. By a quirk of fate, however, they ran into the Japanese instead in Amoy and arrived in Japan later to be flown to occupied parts of Sanya, in order to receive military training from the Japanese Army. They were later moved to Formosa for security reasons and subsequently returned to Burma via Vietnam and Thailand with the Japanese. On 26 December 1941, in a house (owned by a Burmese doctor) in Bangkok, about 25 of the Thirty Comrades had their blood drawn from their arms in syringes, then poured into a silver bowl from which each of them drank – thway thauk in time-honoured Burmese military tradition – pledging "eternal loyalty" among themselves and to the cause of Burmese independence. Their average age was just 24 years. A Japanese officer called Suzuki Keiji, better known among the Burmese by his nom de guerre Bo Mogyo (Commander Thunderbolt) and head of a special intelligence unit called Minami Kikan (南機関) formed in order to support a national uprising in Burma, was the mentor and principal trainer of the Thirty Comrades. The British were driven out of Burma to India during World War II.
