The son of a wealthy Stratholme merchant, Tarquin grew up lacking for nothing but entertainment; it was a shock when his father's business failed and the family relocated to Stormwind City. The young man quickly turned to burglarly and petty thieving, and while showing a natural aptitude, he was picked up by the Stormwind police at the age of seventeen. Fate intervened in the person of SI:7 agent Parwyn Osborne, the "Night Man," who recruited the boy into the Service.
After five years of training and five years as a full Stormwind agent, Tarquin was sent out on a field assignment, to infiltrate the Gilnean mercenary band called the Greymane Exiles and determine their intent; and if necessary, prevent them from accomplishing it. To his shock, Tarquin found that the ideals - "the damned hopeless nobility of it all" - of Sir Nikolai Diaconescu and his company appealed to him.
While hired out to the Alliance defense forces of Guildwatch, Tarquin attracted the ire of the trollish assassin Degmarlee, whose attempt to poison him reached instead an elven druidess named Ceil Nightfury who happened to be in an intimate position that very night. As the brief fling between rogue and druid deepened into an abiding and passionate love, the feud escalated to a war of assassins, with the Horde's Brotherhood of Dusk pitted against the Greymane Exiles and other guilds on both sides taking part.
The war finally ended one bloody night in Stranglethorn Vale, which saw an infamous SI:7 traitor dead, Degmarlee's rage dampened, Ceil left with a maimed and gaping eyesocket courtesy of the dreaded Nim'jhal, the Butcher of Hillsbrad, and Tarquin reeling at the revelations of SI:7's storied perfidy. He resigned his position that day and pledged himself to follow Nikolai and the Exiles to whatever end.
Apart from the hopeless causes of Gilneas, Tarquin kept a personal vendetta against Nim'jhal, one of the most terrifying assassins since Garona Half-blood. It was in part this hatred that led to his capture that summer by the Scarlet Crusade, and subsequent brainwashing at the hands of the Scarlet Oracle Demetria. Believing he could fool the Crusaders, Tarquin agreed to act as their assassin - the Crimson Champion - and was instead fooled into believing all his friends had betrayed him. A massacre of Crusaders at Hearthglen opened his eyes, and then only the judgement of Nikolai prevented Tarquin's life from being taken by one hand or another.
As that year went on, Tarquin became more and more obsessed with killing Nim'jhal, to absolve himself of his failure to save Ceil from injury, a guilt that had plagued their relationship for some time. It was near the winter that the Greymane Exiles took up the cause of Uthas Wordweaver, the paladin who preached peace between Horde and Alliance at any price. Tarquin served as a messenger and bodyguard, and so happened to be at Uthas's camp of Absolution the night that the world went mad.
Nim'jhal, the Butcher, was lurking at Absolution, struck with plague and half-mad. In a chilling and brutal combat, Tarquin killed Nim'jhal, but was struck with a mortal wound himself; when the troll's body rose against as a puppet of the Scourge, it was only the timely arrival of Ceil who saved him from a sure death. Ceil then took him to be healed in Southshore; along the way, he caught what would prove to be his last glimpse of Nikolai. The man he had seen as a surrogate father rode on silently, ignoring Tarquin's fevered moans and Ceil's plea for aid.
When Tarquin awoke five days later, the entirity of Uthas's madness had been revealed - the plague he spread among those he claimed to help, the assassins he sent after Azeroth's heroes, and his final scheme to turn every living, sentient thing in Kalimdor and the Kingdoms into Forsaken - [i]peace at any price[/i]. Tarquin's greatest concern, however, was that his lover, lost to hope and sanity, had followed Uthas and his legions of the dead to Northrend, to battle the Scourge on their own ground. He followed.
The events of Northrend are unknown, and Tarquin claims not to remember much of what happened, being wounded again in that frozen waste, half-starved and delirious when he found Ceil. But find her he did, and through the interference of the High Shaman Matsu'jin and another, unknown party, the pair returned to Azeroth alive and largely sane.
The Greymane Exiles had been shattered in the chaos following Uthas's departure; less than ten remained. Under Tarquin's leadership, the survivors gathered into the Wildfire Riders, an adventuring guild available for mercenary and treasure-hunting work, as well as some more legitimate businesses, largely concerned with watching out for themselves and their own - and remembering the consequences of misdirected heroism.. For himself, Tarquin swore to have nothing more to do with kings, honor, and noble causes; he finally proposed to Ceil, who gleefully accepted.
The Riders set up, using a surplus of cash to set up several legitimate business fronts and buy a controlling stake in the Pig & Whistle tavern in Stormwind's Old Town. It wasn't long before their numbers started to swell, and the mischief began.