He met Princess Cleotrix IV of the Saran Empire at the Planet of Universal Harmony while he was part of the Pan Saran delegation to the First Galactic Council in 2134 and fell in love with the Princess (The daughter of the enemy's queen) They had the same interests and the same vision. They believed peace was possible if Pan Saran and Sarans had a common goal (The protection of Earth's humanity against the Xunx and against the Saran Queen's plan to use the Earth refuges as troops in the Saran / Pan Saran war.
Together they created an underground organization (with members of their respective societies) called Friends of Terra. Goal was it to create a society wide interest and support.
He and the princess worked on this idea and project until their deaths. Marcus Cladius is often called to be one of the founding fathers of the Union Even though he died long before the Union became reality.