Ranulph Shieldbreaker was a True Mandalorian during the Rise of the Empire era. He was a force-sensitive, therefore giving him a high rank in the True Mandalorians. He was the rival of Pre Vizsla, due to the fact that both wielded lightsabers.
Ranulph was born to two peaceful Mandalorians on Mandalore. He was discovered force-sensitive very quickly. The Jedi never discovered him so he lost hope in becoming a Jedi. When he was 12, he was coming home from school when Death Watch captured him and bought him to Concordia. At the time, Death Watch were unknown to all but the True Mandalorians. Death Watch had captured a member of the True Mandalorians so they went on a rescue mission. It was there that they found Ranulph. They rescued him as well as the other prisoners. During the escape, Ranulph used his force powers against Death Watch. The True Mandalorians were surprised and offered him a position in the True Mandalorians. Ranulph joined and learned how to fight. When Ranulph was aged 18, he passed his training. He joined the True Mandalorian ranks and was given gold Mandalorian armour. He also decided to become a bounty hunter. He bought a green double bladed lightsaber which was previously wielded by a Jedi during the Old Republic and instinctively learnt how to use it. He went on many jobs from various people after that, and he also fought many battles against Death Watch.
When the Clone Wars began, Ranulph saw a good opportunity to earn some credits. He didn't go with the Separatists, because he knew Death Watch would form an alliance with Count Dooku, if they hadn't already. The Republic gave him many jobs, and he did every one of them easily. He became the best bounty hunter in the galaxy, since Jango Fett, a fellow True Mandalorian, was killed on Geonosis. He slightly dropped off the radar, however, and Cad Bane became the best bounty hunter in the galaxy. He was busy fighting with the True Mandalorians, and had lots of credits from previous jobs.