The Republic Defense Space Force was founded by the Jedi Order as a means to protect civilian, governmental and commercial craft from pirates and criminals. The Jedi led the force, but many Republic pilots, officers and personnel supplemented the organization. Jedi Masters Dug Anguis and Xian Orrot headlined the Jedi pilot roster of the organization, and they were the unofficial commanders of the organization. The organization was utilized during the climax of the Coo-Neo Crisis and as an elite strike force during the Great Galactic War. It used the R-36 Superfortress immensely during the conflicts, as a tactical and high-altitude atmospheric bomber.
Contrary to its name, the RDSF was more than just a "space force", during the latter years of the Great Galactic War it served as an all-purpose security/police force; it expanded into that role because of its increased enrollment by citizens of the Republic. Emerson Shryne served as the ceremonial Republic commander in the organization and would become the interim commander when Anguis and Orrot were absent.
The organization was created in 27 BBY as a joint venture by the Jedi Order and Republic, to help planetary/local security with piracy, smuggling and other crime. The project was led by Jedi Master's Dug Anguis and Xian Orrot, they served as instructors and as the squadron leaders of the Core Worlds regional roster. The organization spread to a galactic-wide scale by 23 BBY, having squads of RDSF fighters in every sector. Emerson Shryne enrolled in the program shortly after its inception and advanced through the ranks quickly due to a lack of experienced military men.
The RDSF fought in the final battle of the Coo-Neo Crisis. The Coruscant sector and the Telos IV squadrons, led by Jedi Knight Scott Borek, Shyla Spearrunner and Bruce Jammer defeated Coo-Neo's forces. This marked the first major victory against criminal activity for the RDSF in the galaxy. Enrollment doubled the following year.
The RDSF was the first official military organization to participate in the Great Galactic War and served as an interim navy. The RDSF on Coruscant would be absorbed into the navy as an elite starfighter corps, similar to the Shadow Vengeance, and participated in many of the early campaigns. Emerson Shryne saw increasing leadership duty in the organization due to the Jedi commander's increased preoccupation in other campaigns. He served as the commander stationed on Coruscant while the Jedi leaders were away.
The branches in the Mid Rim and Outer Rim would make up most of the regular starfighter squadrons that comprised the Republic's makeshift navy. It formed into the Clone Navy a few years after the war.
The RDSF primarily specialized in drug busts and piracy, the most common crimes in the galaxy at the time of its creation. Additionally, they were tasked with hunting down all the criminals on the Republic's 100 Most Wanted Criminals list. The organization occasionally had to deal with sensitive hostage situations that required the expertise of a more advanced and efficient stealth force; something the normal security forces could not waste credits funding.
Besides armed conflict, one role that became more common for the RDSF during the Republic war effort in the Great Galactic War was riot pacification. They were required to put down riots--primarily violent riots--against the government's leadership by any means necessary; most of the time the peaceful demonstrations were dispersed violence-free, but more raucous riots had to be settled by nonlethal force.
The RDSF was put in charge of protecting the impeached Chancellor, Orasco, during his transportation to Centax 1 for his trial.
Behind the scenes
The RDSF was partially based off of the Coruscant Security Force and also from the Naboo Security Force that was seen in Star Wars Episode I: The Phantom Menace, the first episode in the Star Wars saga.