Leon Larman was born on April 18, 1997, in Montpellier, a city in southern France, and grew up in the nearby town of Brissac. As a young child, Larman showed little interest in sports — until the age of 9, when a visit to a local grappling academy with his father, an avid BJJ hobbyist, changed everything. That single afternoon on the mats ignited a passion that would define the next decades of his life.

Under the guidance of coach David Touzet, Larman quickly revealed both a technical aptitude and a competitive drive that set him apart. That potential came into sharp focus in 2013 when, still competing as a juvenile, he earned a silver medal at the IBJJF European Championship — an early signal that a serious talent had arrived on the French BJJ scene.

David Touzet laid the technical and competitive foundations during Larman's formative years, instilling the disciplined habits that would shape his game at every rank. After earning his purple belt, Larman returned to Montpellier before transitioning to the tutelage of Julien Castanier, who guided him through his brown belt promotion.

Academic studies then brought Larman to Toulon, where he began training alongside one of France's most respected black belts, Julien Gaillard. It was Gaillard who awarded Larman his black belt in mid-2018, completing a journey that had wound through Brissac, Montpellier, and Toulon. Each city, each coach, added a distinct layer to his development — a testament to the depth and diversity of France's grappling community.

Larman wasted no time making his mark following his black belt promotion in 2018. In his debut year at the rank, he swept through the European circuit, capturing gold at the IBJJF Florence Open, Dublin Open, Geneva Open, and Paris Open — an exceptional four-title run that firmly established him as a dominant force in the Peso Leve division (76 kg / 168 lbs).

His consistency carried into 2019, when he successfully defended titles at both the Geneva Open and the Paris Open. Finals appearances at the IBJJF Rome Open and the IBJJF London Fall Open — each resulting in silver medals — further reinforced his standing as one of Europe's most reliable competitors. In 2020, Larman demonstrated his versatility beyond the gi format by claiming the Polaris Squads 2 title, showcasing his adaptability across different rulesets and competitive contexts.

In the period following his black belt promotion in mid-2018, Leon Larman made a defining decision: to set aside his academic pursuits and commit fully to competitive jiu-jitsu. That commitment drove him to relocate to California, USA, where he sought out one of the sport's most technically regarded instructors, Caio Terra.

Integrating into the Caio Terra Association headquarters, Larman immersed himself in an elite training environment and built a close working relationship with Terra. The move marked a pivotal evolution in his career — from a development path rooted in the French BJJ community to the international stage under a globally recognized team. Competing under the Caio Terra Association banner, Larman carries the lessons of his French mentors into a broader competitive framework, reflecting both the global reach of modern jiu-jitsu and his own ambitions within the sport.