Who is Abhimanyu?

The son of Arjuna

Abhimanyu was the son of Arjuna and Subhadra, the sister of Krishna. He grew up in Dwaraka during the Pandavas’ exile and became a brilliant young warrior, as skilled as his father. At the end of the exile he married Uttara, princess of the kingdom of Virata.

The wheel formation

Drona, commanding the Kaurava army, arranged his troops in the chakravyuha, a spinning, wheel-shaped formation that almost no one knew how to break. Arjuna knew, but he had been drawn away to another part of the field. Abhimanyu knew how to break in, but not how to get out. As the story is often told, he heard the secret from his father while still in his mother’s womb, and fell asleep before the end.

He went in anyway. His uncles promised to follow him through the gap.

How Abhimanyu’s story ends (spoilers)

Jayadratha, a Kaurava ally, closed the gap and held the Pandavas back. Inside, sixteen-year-old Abhimanyu fought alone against the greatest warriors of the Kaurava army. They surrounded him, broke his bow, his chariot and his sword, and when he fought on with a chariot wheel, they killed him together, against every rule of war. Arjuna swore to kill Jayadratha before the next sunset, and did.

Abhimanyu’s son Parikshit, born after his death, became king of Hastinapura. Parikshit’s son is Janamejaya, the king at whose snake sacrifice the Mahabharata is told, which is where our story begins.