The first leader of OakClan, FallenStar, had once been a part of ThunderClan despite having outsider roots. As a kit, FallenStar was accepted into ThunderClan from a place beyond Highstones. As they were low on warriors, the leader of ThunderClan accepted the kit. But the kit only. The mother was forced away from their territory and fled to ShadowClan, who were also short on warriors. FallenStar grew up never knowing her parents were outsiders and had always assumed her adoptive parents were by blood. As she grew older and finally received her warrior name, FallenRush, a raid by ShadowClan took place. FallenRush attempted to bravely guard the queens and kits, only to be overpowered by none other than her own mother who had fled all those moons ago. Her mother instantly recognized her, immediately revealing the truth. FallenRush was outraged. So, torn by grief and fury, she snook away from camp one night and traveled beyond the territories of the four clans. She had been good friends with one of the clan's kits, Bluekit, who would later become BlueStar of ThunderClan. BlueKit would never remember the fond times they had together, she was simply too young. 

       As time went on FallenRush grew weak, eventually collapsing at the base of an oak tree. In her dying moment, StarClan took pity on her, granting her nine lives. She was given a quest to form a new clan, all outsiders who had experienced heartbreak and sorrow. 

       She gathered many run-aways from Skyclan, who passed on many tricks and ways of life in the trees, while adding some of their own as well. 

       After forming a small group of cats, FallenRush accepted the name FallenStar and became the first leader of OakClan. The clan now resides in a thick grove of oak trees, safe from most harm from the outside world.