why was yudhishtir known as dharmraj?

Answer 1

Kunti (mother of Yudhistra ) had served Durvasa rishi in her father's house when she was a virgin. The sage, being satisfied with her service blessed her with a boon that she may get children by the grace of any god by calling his name and respective incantation. Pandu, desiring of having progeny, permitted Kunti to get a child by calling a deity. The clever Kunti called Yamadharmaraja, as He is patron deity of Dharma and justice. She got Yudhistira (Dharmaraja) as son through him.

Yama is also the lord of justice and is sometimes referred to as Dharma, in reference to his unswerving dedication to maintaining order and adherence to harmony. It is said that he is also one of the wisest of the devas.

Yudhistira, also called Dharmaraja, king of justice, because of his strict adherence to truth and justice. -