Tamara Rahn was an extraterrestrial and member of the water breathing Banari race from the planet Laab. The planet was destroyed, but she escaped on a craft which headed for the oceans of Earth. The last survivors of the planet were killed by the native Atlanteans who mistook them for invaders.
Namor returned to Atlantis, and was introduced by Vashti to Tamara and her cause. The Atlanteans helped repair her space ship and send her on her way. Seeking revenge for the death of her people, she turned her ship's weapons on Atlantis forcing a confrontation with Namor. Namor subdued her and destroyed her ship. Tamara threw herself at the mercy of Vashti and was put under the guardianship of Namor.
A pompous and arrogant Atlantean soldier, Lorvex, made a pass at Tamara who rebuked his advances. She was later caught in a fishing net and eventually brought to New York City. Namor learned of her capture and made his way there only to be challenged by Thor. Namor engaged Thor but was defeated by the Thunder God. Namor returned home to ponder a full-scale invasion of the surface world. 
Namor put his trust in Lorvex to assemble a force which Namor would lead against the surface dwellers to free Tamara. The invasion was a success in providing a daunting show of force, but Namor was unable to find Tamara as she had been rescued by Lorvex who decided to keep her as a hostage and continue the onslaught against the surface world. Namor defeated Lorvex and rescued Tamara. He then called off the surface attack and after addressing the UN returned to his undersea realm where he was once again crowned Prince of Atlantis. Tamara left Atlantis to live with the Hydro-Men. She was captured alongside them by Attuma, Doctor Dorcas and Tiger Shark, but was saved once more by Namor.
Tamara is later found among the Atlantean terrorist group the Fathom Five. However, she was acting as Namor's inside agent, though she wasn't able to prevent an attack on Beijing or Manhattan.  It was revealed that when Radioactive Man attacks Tamara due to her being part of the Fathom Five, he planted a radiation onto her that, while is harmless to Tamara, will kill the Atlanteans once she returns to their camp.