Japanese sun goddess in Earth mythology and Goa'uld who came to power as a System Lord during the final years of Goa'uld dominance in the Milky Way Galaxy. Amaterasu was among the delegates that were dispatched by the System Lords to visit Earth.
During desperation in the negotiations, Amaterasu and the others ordered the approach of a Goa'uld Ha'tak in the hopes that the ship would force Earth's hand and demonstrate the power of the technology (or lack thereof). But Baal's forces intercepted and destroyed the ship.
Amaterasu and Yu departed Earth without Camulus, who had recently requested asylum. The sun goddess instructed Dr. Weir to inform Camulus that he would be forever remembered as a traitor and coward.
New Order, Part 1 - Amaterasu joins the Goa'uld System Lord delegation for Earth in the hopes of taking advantage of their Ancient weapon before their power base is overrun by Baal.
New Order, Part 2 - Their negotiations a failure, Amaterasu and the others depart from Earth.
It's Good To Be King - Tok'ra intelligence reports that Yu and Amaterasu are rallying their armies for a final stand against Baal.
Reckoning, Part 1 - The Free Jaffa prepare to engage Amaterasu's fleet but soon realize it has been taken over by Replicators.
Ripple Effect - In an alternate reality an alternate SG-1 reports that Amaterasu was the former ruler of PX7-445, rather than Baal.