Stargate: Every System Lord Ranked Worst To Best

Not an awful lot is known about Amaterasu prior to her appearance at the SGC, seeking an alliance with Earth after the destruction of Anubis's forces. She joined Yu and Camulus in their attempts to ally with Earth, thus gaining a degree of control over the Ancient weapons platform in Antarctica. However, once she learned that the platform was no longer working, she implied that she could leak this information to Ba'al - posturing from the death throes of an alliance that would never come as it was.

That was the last time that the SGC encountered her. With the rise of Ba'al in power, it is unknown what became of her and whether she survived or not though, if the fates of many of the other System Lords are anything to go by, she probably fell to Ba'al's Kull Warriors as well.