Trassitan was a celestial body situated within the Trassitan system. This system was part of the Veragi sector, found within the New Territories region of the Outer Rim Territories. The Veragi Trade Route hyperlane provided a connection for Trassitan to both the Veragi system and the Dubrillion system, which was located in the Myto sector.
By the year 22 BBY, Trassitan housed an office belonging to the Judiciary of the Galactic Republic. This office was the closest of its kind to the Gree Enclave, a specific area within the Veragi sector. In that year, Count Dooku, the leader of the Separatist movement, was observed on the Rokak'k Baran. This massive transport starship was the primary mode of transportation inside the Gree Enclave. Subsequently, a merchant operating in the area relayed a report of this sighting to the Judiciary office that was located on Trassitan.
The initial mention of Trassitan occurred in HoloNet News Vol. 531 #54, a part of the HoloNet News website that went live on May 2, 2002. The reference book The Essential Atlas, published in 2009, identified the Trassitan system, and therefore the world of Trassitan, as being located in grid square L-3.