He was the Vala responsible for participating in war and the last of them to descend into Arda, coming to the aid of the others when he heard of their war with Melkor.
Having heard of his fellow Valar's struggle against Melkor, Tulkas was the last of the Valar to descend upon Arda, thus tipping the scales of battle against Melkor. Melkor fled before him, and the Spring of Arda was begun.
After the Two Lamps were erected and the Valar had made their first dwelling at Almaren, Tulkas wedded Nessa in a great feast. Being weary and content he slept, and Melkor decided his hour to retaliate had come.
When the Children of Ilúvatar awoke, there was a council among the Valar regarding Melkor. Much to Tulkas's delight, it was decided that Melkor should be removed. During the War for Sake of the Elves, he wrestled with Melkor and bound him with Angainor, which was forged by Aulë.
Upon Melkor's release from captivity, Tulkas remained vigilant and distrustful of him.
