Aquaman

The origins of Mera are not clear, but she came to earth from a watery dimension. This occurred early on in Aquaman's career. She befriended the King of Atlantis, Aquaman, in her first adventures. She would eventually fall in love with him, and they would marry, making her the Queen of Atlantis.

Death Of A Child

Some time afterward, they would have a child. But the child would be lost at the hands of Black Manta. The trauma from said incident would drive her to leave her husband.

Briefly stuck in the hellish dimension called the Netherworld she has since returned. She remains estranged from Aquaman, despite hints of lingering affection, and reigns as the Queen of Atlantis after Aquaman's exile. However she is merely a puppet queen for the new Sorcery Elite, and was recently punished by the sorcerers of Atlantis by being turned into an air-breathing human maiden.

One Year Later

After the events of "One Year Later", Mera regained her water breathing abilities, if not her full strength, and became the leader of a small rebel army, taking under her protection some refugees from the lost Atlantis, and the new Aquaman.