Before the Mahabharata war, a Kshatriya with a flawless body had to be sacrificed. In the Pandavas camp, only Krishna and Arjuna had flawless bodies but they couldn't be sacrificed. So Aravan came forward and offered him on the condition that he wanted to marry before he dies.
Aravan or Iravan is the son of Arjuna and Ulupi, the Naga Princess who came forward for the ritual.
Is that true that Aravan was sacrificed in the pre-war of Kurukshetra?