"The Xeno series is a metaseries of science fiction Japanese role-playing video games. The series is the brainchild of Tetsuya Takahashi and has been published by several companies, including Square, Namco, and Nintendo.
Initially envisioned as a six-part series started with the game Xenogears, the series could not be directly continued due to the developers leaving Square, who held the legal rights to the property. This led to an exodus of the development team to Namco, where the Xenosaga series was started, not as a direct sequel or prequel, but as a new series with thematic connections. This too was envisioned as a six-part series, but instead was cut short to only three parts, after the completion of Xenosaga Episode I, Episode II and Episode III. After the ending of the Xenosaga series, Monolith Soft was bought by Nintendo, and a new Xeno game, Xenoblade Chronicles was developed and released. In January 2013, Nintendo announced a new game by Monolith Soft, yet to be titled, but many journalists in the industry speculate to be connected to the Xeno series due to similarities of the game's trailer and involved staff."
Source: Wikipedia, "Xeno (series)", available under the CC-BY-SA License.