Countess Regina Barthalomew was a holographic figure created aboard the USS Enterprise-D as a character in one of Data's holoprograms based on Sherlock Holmes. She was designed as a romantic companion for James Moriarty.
When she was seventeen, she went on safari in Africa with her uncle. Her mother was frightened her daughter would be bitten by a tsetse fly. Regina enjoyed her time in Africa, where she took to wearing trousers. Upon returning home, she found it hard going back to a corset. After that, Regina never stopped traveling. She could not stay in one place long and was looking forward to the next new experience.
In 2369 Moriarty, who had become self-aware, briefly commandeered the Enterprise-D in order to win his release from the holodeck. After Captain Jean-Luc Picard convinced Moriarty that he was released from the holodeck, Moriarty asked that Regina also be released so he could spend his life with her. He was given a shuttlecraft, and Regina set off with him on a voyage through the galaxy. Unknown to them, it was a holographic trip, a ruse devised to convince Moriarty to return control of the ship to Picard. At the start of their journey the Countess expressed a strong interest in visiting Earth. (TNG: "Ship in a Bottle")