Uttara Vivaha Parva is the forty-eighth upa parva included in the fourth maha parva, namely the Virata parva in Mahabharata. Vyshampayana had narrated the historic events to Janamejaya on his queries.
What was the role of Draupadi in Uttara vivaha?
After the death of Kichaka, the servants of queen Sudheshna reported to her about Sairandhi, the lady Draupadi in disguise, as she had caused his death. Kichaka was her brother and an able army commander of Matsya. The death of such a strong person may cause adverse effects to her Matsya country, and the queen thought to expel Sairandhri out of her country and informed her accordingly. Sairandhri sought a period of fifteen days to find out another placement suitable for her, and sought her unconditional pardon and begged for life and praised the queen for her generosity since she had provided food and shelter until that date.
In addition to her praying words, she had assured Sudheshna her husband is an invisible Gandharva then but could be able to provide full security to Matsya with internal security as well as border defensive force. If any chance of threat is found to Matsya, she could make use of that Gandharva to provide full security to Matsya. Sudheshna granted her fifteen days and Sairandhri promised her in the later times, she would serve both her majesty and her daughter princess Uttarakumari and try to help the queen to give away that princess in marriage since then her education was almost completed.
What was the role of Kanka, Yudhishtira in disguise in Uttara vivaha?
When Susharma, the king of Trigarta attacked Matsya and sacked Virata to his country along with some cattle of Matsya, Kanka ordered the palace cook, Bhima in disguise, to free him from the grip of enemy soldiers. He ordered Nakula and Sahadeva to fight by gathering the Matsya army and to drive away the enemies back into Trigarta, and succeeded in the task. These services of Kanka forced Virata to take him into greater confidence. Kanka was his personal advisor in administrative matters. Gradually, Virata was also thinking to get the advice of Kanka on the matters of the marriage of Uttarakumari.