It began when a sorceress came to the courts of the Aesir. She was beautiful and elegant, with long raven hair and a black dress. She showed the Aesir many tricks of Seidr. Seidr was ancient magic that manipulated the fabrics of fate. Those who used it well could foretell the future, change the weather, call wild animals to them, and even heal the sick.
The Aesir had never seen such magic before and were amazed by it. But seeing how it altered the world around them, they soon grew suspicious of it. They decided to throw the sorceress in prison. Little did they know, however, she was no mere sorceress but Freya, the high goddess of the Vanir clan.
The Vanir were furious when they learned one of their goddesses was being held prisoner by the Aesir. They stormed Asgard and tore down the walls around it. Without a moment’s hesitation, Odin took up his mighty spear, and the Aesir went to war.
With their superior weaponry, they managed to push the Vanir back. This didn’t last, however, and the Vanir, with their mastery of magic, fought back.
The two forces were at a stalemate. It seemed like the war would go on for aeons. The only way out of this mindless violence was to agree to a truce. Each clan would send hostages to the other clan in exchange for peace. From the Vanir clan, Freyr, Freya, and Njord were sent to Asgard. And from the Aesir, Hoenir and Mimir were sent to Vanaheim.
As time went on, the Vanir grew dissatisfied with their trade-off. They had sent three of their most esteemed gods to the Aesir, while the Aesir had sent them what appeared to be an old man and a simpleton. They decided to send their two hostages back. Mimir, however, refused to return to Asgard and instead went to Jotunheim. Hoenir chose to return.
It seemed a new truce had to be made. Freyr, Freya, and Njord had all been treated well by the Aesir and had no intention of returning to Vanaheim. So it was decided that, instead of sending more hostages to the Vanir, each god would spit in a cup, and from the spit, a new god would arise. That god would then join the Vanir clan.
Kvasir was the god that arose. Because he was of both Aesir and Vanir blood and was far wiser than anyone who came before.