Why did Draupadi have five husbands?

Draupadi was born from a fire altar, with her brother Dhrishtadyumna, to King Drupada of Panchala. At her svayamvara the test was to string a heavy bow and shoot a rotating target through a ring, seen only in a reflection below. The Pandavas were in hiding at the time, living disguised as brahmins after escaping the house of lac, and Arjuna, dressed as a brahmin, made the shot.

The brothers came home to their mother and, as they always did, called out that they had brought alms. Kunti, busy inside and not looking, told them to share whatever it was among themselves. Her word, once spoken, could not be unsaid, and Yudhishthira held that a mother instruction had the force of law.

The epic knows this is not a normal arrangement and argues about it at length. Drupada objects that one woman for five brothers is against custom. Yudhishthira answers that the ancients permitted it and that their mother word binds them. Vyasa then gives the deeper reason in private: in a former life Draupadi had asked Shiva five times for a husband with a particular virtue, and was granted five husbands accordingly; another telling identifies her as the shared consort of five Indras. The narrative also supplies a practical reason, since Yudhishthira had seen that Arjuna prize would otherwise divide the brothers.

The marriage carries rules. Draupadi lives with each brother for a year in turn, and no brother may enter while she is with another; Arjuna breaks this and exiles himself for a year, which is how he gathers other marriages and alliances. She bears one son to each of the five, and all five are killed in their sleep by Ashwatthama after the war.

The arrangement is also why her humiliation in the assembly hall implicates five husbands at once, and why her anger, unlike theirs, never cools.