The career of Tylok I started in Shadowdale with his half-elven friend Lywin. They were adventurers first; although they showed signs of heeding some higher responsibility, particularly in defending Hlondeth against the Warlock Siege, they never really took anything seriously. In his middle years, Tylok made his living off battling the denizens of the Ffoul Mountains, mostly to gain access to their rich troves of horded treasure. The extent of his efforts, however, were so great that some historians have commented that he single-handedly delayed for a generation the local onset of the Days of Darkness.
No matter what the historians say about the beneficial side effect's of Tylok I's career, his offspring undoubtedly were a bane to mankind. Mostly ignored as a dullard by his father and beyond his mother's control, Tylok II was a successful student of warfare and used his father's wealth to develop his own assemblage of power. Taking advantage of the lack of central authority in the southern city-states, he amassed an army of mercenaries to deal with the increasing security concerns in the area. Proclaimed as a hero for fending off the orc hordes from the Ffoul Mountains, Tylok was able to operate free of any authority despite his growing power.
Half-way through his career, though some say earlier, Tylok II struck a deal with the Dark Invaders to provide them entry to the continent. Leaving his captains in charge of his army's activities in the South, he and a contingent of his best warriors crossed the Steppes of Arachine and began to build the infrastructure for invasion in the otherwise peaceful Northern Villages. His work was hardly what one would expect from a seasoned military veteran; indeed, taking orders from distant powers he barely understood, he rarely fathomed the tasks he and his mercenaries were asked to do. Rather than building an army, constructing military encampments, or seizing land, they were asked to place rocks in particular locations, journey to strange locations for no apparent purpose, and perform other mysterious missions.
Tylok II never "settled down", so the man who claimed to be Tylok III has often been denounced as a fraud. However, many clues indicate that his relation to Tylok II is real, including the timing of his appearance in the Northern scene. Whether by blood or by coincidence, the two did develop a bond, and Tylok III worked on many his "father's" more down-to-earth missions, which probably had little to do with the Dark Invasion.