NOTE: This article regarding Leon's history mixes Canon with non-canon.
Leon Belmont was the first known chronological Belmont. After his betrothed, Sara Trantoul, was kidnapped by Walter Bernhard, Leon renounced his knighthood and was disgraced. He was stripped of his armor, piece by piece, his shield was smashed, his spurs cut off, and his sword broken in half. Even with no way to defend himself, Leon met with an alchemist named Rinaldo Gandolfi, who gave him an alchemic whip and a magical metal gauntlet. During Leon's quest, he met and developed a rivalry with a traitorous vampire named Joachim Armster. After Sara's death by the hands of Leon's former comrade, Mathias Cronqvist, her soul bonded to the alchemic whip, creating the Vampire Killer. After dueling against Death himself and winning, Leon swore that the Belmont family would forever hunt the night.
Leon would apparent find another woman whom he would fall in love with. After their daughter, Sonia Belmont was born, she inherited the Vampire Killer. Leon would later father another child, Sala Belmont.