Berra was the wife King Thar, and is the mother of Garth. King Thar was king of the Idylists, a peaceful group of Atlanteans, who lived in self-exile for over 4,000 years from Poseidonis. Her husband had bound his brother Slizzath in a other-dimensional prison. This is when her husband, King Thar, died, leaving Berra alone and pregnant. The Idylists, fearing that the monarchy was now tainted banished Berra from their home, and she went to Poseidonis for safety.
A Baby is Born
But things were not going to get better for Berra. For when her child was born, a boy, she looked into his eyes and saw they were purple, the Idylist mark of power. Berra believed that meant that Garth would one day undo her husband's final act, and release Slizzath from his prison. So, feeling that she had no other choice, Berra had Garth, her son, abandoned on a reef to die. But Garth survived. He did not know of his parents, of who they were, until much later in his life. And Berra was right, Garth did eventually release Slizzath from his prison, but he did manage to return him to his prison.