MARKANDEYA PURANA

Why did Draupadi marry all the five Pandava brothers?

 Apprehending the severe penance of Trishira, the son of powerful Brahmana Twashta, Indra suspected danger of his own position and thus killed Trishira. Twashta went into a rage and plucked a strand of hair from his head and offered it in the homa kunda (Fire Pit) by his mantrik power and created the mighty Vritrasura whose mission was to kill Indra, who had already lost his sheen since he committed a Brahmana. Indra deputed the Sapta Rishis to strike a deal with Vritra so that he would not put Indra to immediate danger; but Vritra was killed unawares by Indra.

These actions angered the community of Rakshasas resulting in continuous warfare against Devas and Prithvi felt great burden of the atrocities by the demons. Prithvi appealed to Indra and the Deities who in turn took the forms of Pandavas:
Yadindradeham cha Tejasthanmumocha Swayam Vrishah,
Kunthyamjaatho Mahatejaastatho Raja Yudhishtarah/
Balam mumocha Pavanastatho Bhimo vyajaayat,
Shakraveeryardhatas chaiva jajney Paarthom Dhananjayah/
Utpanno Yamalou Maadriyam Shaka Rupou Mahadyuti,
Panchadhaa Bhagavannityamavateernah Shatukratuh/
Tasyotpanna Mahabhaaga Patni KrishnaHutaashanat,
Shakrasyaikasya sa Patni Krishna naanyascha kasyachit/
Yogeeswaraah shareeraani Kurvati bahulaanyapi,
Panchaanaameka Patnitwamityetatkathitham tava/

(Dharmaraja himself from the body  of Indra deposited his virility into Kunti from which was created Yudhishtara. The Deity of Wind viz. Pavan deposited Indra’s radiance into Kunti as a result of which Bhima was born. Indra gave away half of his ‘Shakti’ to Kunti and Dhananjaya was thus born. Indra’s virility was transferred through the two Ashwani Kumars to Devi Maadri and was born the pair of Nakul and Sahadeva. Indra’s ‘Amshas’ (alternatives) were manifested among all the five Pandava brothers clearly. Moreover, Indra’s wife Shachi Devi as Yagnaseni was created from ‘Agni’ and hence Draupadi was Indra’s own better half.Yogeswar Purush Indra could divide his own radiance into as many parts as per his volition. Hence, it was amply justified that Draupadi was indeed the common wife of the five Pandavas as asserted by the Holy Birds to Sage Jaimini in response to the Sage’s doubt.