Shalya against His Nephews

King Shalya of Madra, the maternal uncle of Nakula and Sahadeva, heard that his nephews the Pāṇḍavas were preparing for war, and he mustered a great army and marched to join them. But Duryodhana learned of his coming, and devised a cunning trick to steal him away.

Along the whole route of Shalya's march, Duryodhana had beautiful rest-houses built, and lavished upon Shalya and his soldiers such splendid feasts and hospitality that Shalya, assuming all this bounty came from his nephew Yudhishthira, was deeply moved, and called for the host to be brought so that he might reward him. And at that moment Duryodhana stepped forward and revealed that he himself was the host.

And Shalya, a man of honour, was stunned, but bound by his own gratitude, and asked how he might repay such hospitality. And Duryodhana at once demanded that Shalya fight on the Kaurava side. And Shalya, held fast by the ancient code that one who has eaten a host's food is indebted to grant his request, agreed, though he bitterly regretted that he had been tricked into betraying his own nephews.

Then Shalya went on to Upaplavya to confess his mistake to Yudhishthira. And Yudhishthira, hiding his disappointment, acknowledged that the promise was binding and must be kept. But he made a request, for he knew that Shalya was the equal of Krishna in the driving of a chariot, and that Duryodhana would surely make Shalya the charioteer of Karṇa in his final duel with Arjuna. When that hour comes, Yudhishthira asked, use your place to dishearten Karṇa, to deflate his pride, to weaken his spirit, and so protect Arjuna's life.

And Shalya agreed: he would fight honourably on the Kaurava side, as his vow required, but he would use his tongue, as Karṇa's charioteer, to undermine Karṇa's confidence and so shield Arjuna. So even among the enemy's forced allies, the Pāṇḍavas had a hidden friend.