Darth Cyrus was a human male born around 253 BBY, he set out on a journey throughout the galaxy, taking fake aliases everywhere he went. He progressively formed a group of force-sensitive warriors he called Cryptum. Members of the group were often very strong with the Dark Side.
Between 130 ABY and 141 ABY, Cyrus visited several independent realms in the galaxy and corrupted them into joining him, forming Dark Reach with himself at the top of the organisation. Cyrus and his allied waged a war against the Galactic Alliance Triumvirate, later reorganised into the Federation of Free Planets, dubbed the Infinity War.