Rose Hayes was the daughter of the British aristocratic Hayes family. Having been born in a time before women were admitted into the Century Club as members, she had a typical noblewoman's upbringing... for a time. During her childhood, her closest friend was her poorer cousin Henry Maurice Allard. They both chafed and rebelled against their respective social roles but, as it turned out, in drastically different ways; while Rose would go on to become a bounty hunter and assassin capturing or killing evildoers for her idea of justice, Allard, born a day before her, would become the White Scorpion, an international criminal mastermind. His schemes to take over the Hayes inheritance, at any cost, have made a clash inevitable - if it was not already given his obsession with Rose. They would fight time and again, neither being willing to do what it took to end the game. Ultimately, at some point around 1885, Rose caught him, tortured him and abandoned him in the most distant part of the jungle, ensuring that he would go insane, but, thanks to his Shadow Centurion status, would not die; in the light of the things he did or tried to do, it seemed to her entirely fair at the time, though perhaps less so later.
As a bounty hunter, Rose was characterised as being relentless and self-righteous, rationalising taking lives with her own idea of justice at odds with normal laws or morals. Over time, however, the certitude that drove her became less dominating, or perhaps simply took a different form.
After 1850 she was able to become one of the first female members of the Century Club. Working alongside other Centurions softened her attitudes slightly, but not entirely. She ended up part of the team led by Manfred von Richthofen, growing particularly close with John Spencer, a man she shared some interests and ideals with. Ultimately, however, the one who changed her fate was an enemy, a Shadow Centurion known as Masque. She found his ideals and determination oddly appealing, even as she continued to reject his reckless, terrorist methods and work to thwart his schemes. The final straw, as her own conviction was worn being away, was the Zanzibar Incident of 1901, during which Masque has almost burned down the city of Zanzibar - and also broke up the underground slave trade, something the Centurions failed to do for decades. As it happened, Rose had him at her mercy when his escape plan fell through, but was unable to kill him. Instead, she let him go and herself left the Century Club to travel Africa as a wandering protector and healer (aided by the magicks she picked up at some point in her travels), becoming known as the White Lady in tribal legends, having successfully reinvented herself as a pacifist healer aloof from the morally gray struggles of the outside world.
Before they split paths after Zanzibar, she and Masque found two orphans in the catacombs that no one else would claim and that they soon realised were new Centurions. Rose took the girl she named Sarah and raised her as her own, teaching her everything she knew and letting her help out in her later journeys. Likewise, at some point she gave Masque the magical life-preserving rose quartz necklace that was made for her by Allard, perhaps to keep him alive despite some inexplicable and persistent condition that defied his Centurion nature. In the meantime she kept her contacts with both Masque and the Centurions to a minimum, John Spencer being one of the few occasional exceptions. On encountering an unusual disease she could not defeat in early 1914, she took it into herself to save her patient and consequently died. She is now dead. Before she was quite dead though (as she is now), she told Sarah to travel to Britain and deliver a letter to John. In the process, whether she realised it or not, she threw Sarah headfirst into the world of Centurions and Shadow Centurions that she had never really prepared her for.
In any case, dead.