(The following is patched together from multiple sources, primary of which is A Hermetic History, a huge 14-volume series of which the library has an English and a German translation. It was completed while he was still alive – the print date is 1983 for the edition you have here, which is the 27th edition. The first printing was in 1315)
Master Criamon, of course, can identify himself with various incarnations in the past, and makes the reliable claim that his Avatar contains a shard of that attributed to Hermes Trismagestis* himself before his destruction at the hands of the nascent Order of Reason in the thirteenth century (according to most sources). His first concrete manifestation, however, was in Prague in 1521. He joined the Hermetic Order during the end of the Tremere War* and was instrumental in reinforcing the first Doisstep* Chantry in Hungary. He was very quickly identified as posessing a very powerful Avatar and bearing an equally powerful mark of Fate, he quickly ascended through the Mysteries and was accepted as an Adept of House Criamon (whose surname he obviously took as his own) at the age of 15.
His first noteworthy act was to challenge the Tremere known as Etrius* to Certamen* and defeat him, using the weaknesses inherent in the Tremere’s particular transformation against him. He did not destroy Etrius, but the victory in Certamen is credited with leading to the end of the Tremere War. For this, Master Criamon was raised to the status of Master, an honor which he soon earned spontaneously during the Certamen duel.
Alonius was able to solidify Doisstep’s defenses and under his guidance it became the most powerful Hermetic Chantry then or since. At this point, his development was frustrated. Though he did not dare take the path to accursed immortality which the Tremere chose, he nontheless was frustrated by the constraints of a mortal lifetime. To overcome this, he developed a rote to affix his Avatar to his consciousness, memories and knowledge, and sacrificed himself, with the help of Apprentices under his tutelage at Doisstep.
Though the Primus* of the Order condemned this act, Master Criamon did in fact return, with much of his knowledge and previous personality intact, and quickly rose again through the ranks of the Order. Between incarnations, House Criamon had been essentially disbanded, and so when Master Criamon was raised once more to that title, he placed himself in House Miscellanea*, which was then a political coalition of lesser Houses. He rose to the title of Archmaster* of Forces and then of Matter, Spirit and Prime as well. He ascended to Oracle* and joined the other five Oracles at the time, who were heads of House Shaea*, Janissary* (who were previously known as the Ksirifai* of the Order of Reason*), Quaesitor*, Solificati* (another Tradition absorbed by the Order) and Flambeau*.
Master Criamon’s quest for power continued, and he was raised to Primus of the Order in 1766, a position he holds to this day. In an act of desperation and perhaps hubris, Criamon ultimately chose to excise from his own Avatar his ability to utilize Forces, the hallmark of the Order of Hermes. It is said that through the sacrifice he was able to make his only progress toward Ascension in 200 years, but the Council and the Oracles believed that this was too reckless an act and he was removed from his position as a result. Though he remained Primus in technicality, another representative was sent from the Order of Hermes to the Tradition Council* for the next hundred years, until after the turn of the century.
As Technocrat* attacks on Doisstep and other Chantries increased in power and frequency, Master Criamon re-emerged with the proposal to transmute the entire Chantry and the town that had grown around it into the Deep Umbra*, a place where the Traditions were still more powerful than the Technocracy. The proposal was accepted, and with a great deal of assistance, he was able to accomplish the transformation as well as translocation of the entire area, leaving hardly a footprint behind. In the midst of the rote he also trasformed himself from a living being into a kind of Umbrood* so that he could live in the new Doisstep permanently. It is said that this momentous act not only saved Doisstep for almost a century, but also led to a further step toward Ascension.
Once Doisstep was firmly orbiting along the Horizon*, the Tradition Council began to meet there on a regular basis, and the Order of Hermes rose to a position of greatest influence in its history. Master Criamon was made head of the Council itself and officially raised to his previous position of honor in the Order.
Master Criamon moved on to create an entire Shard Realm* on the Horizon to contain Doisstep as well as hundreds of visitors from the other eight Traditions. Each was granted its own region of the Shard Realm. The final creation, when complete, was a fully integrated and living world with its own rules-set, continuity, and Paradigm. It is the achievement that is closest, to date, of the creation of a shared realm useful to all nine Traditions, and is widely hailed as the most important achievement in the history of Awakened beings.
Currently Master Criamon’s research and writing has turned to the subject of Ascension*. Much of what he produces is intended only for Archmasters and Oracles, those most advanced along the Mysteries*, and he is often deep in conversation with powerful members of other Traditions on the topic. It is hope that this achievement will end the eponymous War which has cost so much, particularly in this century.
At this point, Master Criamon has mastered the Spheres of Correspondence, Life, Matter, Mind, Prime and Spirit, and has great facility with Entropy and Time. He lacks facility with Forces, of course, given his long-past and perhaps ill-considered sacrifice.
(the *s represent subjects that you find are cross-referenced through the arcane apparatus of the series with a list of other references to those topics.)