Karn, the silver golem, is the creation of the planeswalker Urza. Karn was the first part of Urza's Legacy—a collection of artifacts that Urza created for the purpose of destroying the Lord of the Wastes, Yawgmoth, the dark lord of Phyrexia. Urza had experimented with various metals and the effects going back through time had on them. Finally, Urza discovered silver was the only metal that could go through the portal unharmed. Thus, the silver golem was created.

Ironically enough, Karn's life matrix, is actually the heartstone from the Phyrexian sleeper agent Xantcha, who became Urza's good friend. The heartstone has no trace of Phyrexian origin now. Xantcha's heartstone was recovered from a battle Urza fought against the Phyrexian praetor Gix.

Urza and Barrin named the golem Probe 1. When the golem was allowed to socialize with the other people of the Tolarian Academy, the golem met the young student, Teferi. Teferi suggested a new name, which he guaranteed would bring a smile to anyone's face: Arty Shovelhead. The golem later met his first true friend, Jhoira, who gave Karn his current name, after the Thran word for strength.

After Jhoira left the Tolarian Academy, it became increasingly difficult for Karn to focus on his tasks. Karn never forgot anything and became very sad from old friends leaving as the decades went by.

Urza and Barrin decided to limit Karn's memory to 20 years so that he wouldn't be haunted by events from the distant past. Karn became very concerned about forgetting his friends, particularly Jhoira. So, every night, he told himself: "Jhoira is my friend—my best friend. We met in the original academy, before the accident drove us from Tolaria. She named me, Karn, from an old Thran name. She said it meant strength."

Urza sent Karn to work onboard the flying ship Weatherlight and has helped the various captains as the years went by. In Benalia, a Phyrexian attack killed many of the Capashen people, with only a single survivor. Karn saved the small boy, who's name was Gerrard. Since then, Karn has served as Gerrard's protector. Due to accidentally killing an innocent bystander once, he has vowed never to kill again, not even if it meant saving Gerrard. To be continued . . . .