During Batman's early years, a stunt man named Hudson Pyle wanted to be a superhero. At first, his reasons were selfish since he wanted to gain fame but began to change into more honorable ones. During his time, he was famous for his sharp swords and quick wits and even his handsome smile. However, his superhero days began to come to an end when he fell in love with a young woman who was being blackmailed by some gangsters. The gangsters learned about her connection to Cavalier and blackmailed him into committing crimes for them. The Cavalier's fame began to deteriorate and driven to the edge, he killed his blackmailers. This led to a fight with Batman and the police where he was gunned down by the police.
Note: This Cavalier appears in Legends of the Dark Knight #32 in the Blades story arc. Cavalier I has been identified as one of the deceased entombed below the Hall of Justice.
The 'New' Knight
Years later, after Batman and Robin had become partners, a new Cavalier surfaced. His name was Mortimer Drake, an antiques collector who couldn't get enough. Drake began to dress as the Cavalier and started to rob museums, collectors, anywhere he could find valuable antiques. Drake later faced Batgirl ( Barbara Gordon) and Batwoman and found himself at a dead end. He couldn't hit a woman and had to resort to a self-examination, then he thought, "the Devil with gallantry" and punched Batgirl in the face. During the Knightfall story arc, he had apparently gone insane for reasons unknown. It's possible his origins have changed since Crisis on Infinite Earths.
One Year Later
Mortimer Drake is now working for Black Lightning as an informant, it could be that he has now reformed. He is also said to be in a gay relationship with Captain Stingaree. His back is later broken by Bane, and he is reduced to acting as a bodyguard for Leslie Thompkins. His back was broken while battling the Secret Six alongside othervillians. Captain Stingaree was confirmed as a casualty. It is unknown how severe the break was for the Cavalier.
A new Hush in Gotham City is using the motive operadi of former Batman villains. This new Hush tries to murder the Calendar Man with Cavalier's sword but his attempt was interrupted by Terry McGinnis. Terry engages in a brief dialogue with this new Hush and his choice in weapons. Terry reveals that Mortimer Drake, formerly known as the Cavalier, has been dead for quite sometime.
He appears in Secret Six briefly as one of the villains tracking down the Secret Six. During the brawl on the bridge Bane performs a Backbreaker on him probably breaking his back.
For more information see; Batman: The Dark Knight: Knight Terrors
Cavalier is one of many villain injected with a combination of Venom and Fear toxin. The Venom makes him super strong and the toxin makes him fearless. He is taken down by Batwoman, in Devil's Square.
Batman: Brave and the Bold
Cavalier appeared in "The Eyes of Despero!" just long enough to speak in really bad Shakespeare-esqe dialogue before Batman stops him.