Kozek is believed to have been born in B.G.A. 3310 on the Arcol Steppe, probably in the Buroak Temple, one of the larger city-states of the region. Very little is known about his parentage or childhood, but given his later accomplishments, historians suspect his father was a high priest and his mother a chantress of considerable acclaim. For a long time, antiquarians believed they had identified his mother and father from extant records, but the two individuals named were later determined to have lived roughly two hundred years apart.
In any case, by the middle of his life Kozek had become a high priest in his own right, not a small feat in a temple of that size. That he would become a litch was never in question, but Kozek demanded more than to become a mere necrosage. At that time, the necromancers did not support ritual suicide; to take one's own life was considered a sacrilege. Although there was no penalty or shame attached to the practice, it was still considered highly unorthodox when, about the age of fifty, Kozek took his own life to begin his immortal litchdom.
Because he had taken his own life at a (relatively) young age, Kozek had few supporters within the temple. Whereas raising a Shade or reanimating a corpse is trivial, the process of creating a litch requires many dedicated rituals, plus coveted space within the Sanctum Satorum; not to mention the complex and challenging process of embalming and maintaining the body. While it can be done in less, the typical time between death and litchdom was then around five hundred years; and as such there were very few litches. In Kozek's case, he languished in death for two hundred years before his glorious rise.
Kozek's litch rose close to the end of the Golden Age of Necromancy, at the height of Necromancer civilization and power. However, it was also during a time of great unrest. While their culture was at its zenith, the threat of conquest from without was stronger than it had ever been. It may have been in reaction to this peril, in combination with his own desire for power, from which he derived the Grey Temple ideology.
Tomb-sweet-tomb. In Kozek's case, far from elaborate by litch standards, though still well-furnished with murals, false doors, altars, bells, and censers.