Tara Markov, half-sister of Brion Markov (Geo-Force), was the illegitimate daughter of the King of Markovia. While in Markovia, she came under the care of a Dr. Helga Jace and, through her experiments, Terra obtained Earth manipulation powers—specifically, the ability to control all forms of earthen matter. After obtaining these powers, her father requested that she leave Markovia for the United States, to prevent the scandal of the king having an illegitimate daughter from becoming public. Unlike her more heroic brother, Geo-Force, Terra had deep-rooted psychological issues including malignant narcissism, believing that, with their powers, they should rule Earth rather than help the weaker masses.