In the beginning was the Order of Hermes, and its most devious practitioner, House Tremere based in Chantry Ceoris in Transylvania. Around the time of the first Millennia [1000 AD] The Order realized the world was running out of the stuff of Magic. 
Goratrix of House Tremere captured a Tzimisce Elder and used him to learn some of the secrets of the Kindred. He sacrificed his two apprentices to the study and within a few years [AD 1022] Goratrix had learned how to make Kindred. 

Tremere and his 7 most trusted advisors became Kindred and began spreading vampirism through out House Tremere in secret. The Tzimisce Lords of Transylvania and local Nosferatu and Gangrel banded together to attack Tremere Chantries with a great deal of success. Goratrix managed to craft Gargoyles from captured Tzimisce and Nosferatu and with these under their control the raids ended. From fighting Tzimisce of all generations, Tremere learned that the older the generation the more potent the Blood. He located the havens of several torpored Antediluvians, and in 1133 AD diablerized Saulot. Soon after Tremere went into Torpor himself, and the Council of Seven established geographic areas for each to work in.

The Inquisition began, and Goratrix attempted to bring the Church under his sway. Instead he brought the Inquisition down upon the Kindred population in Europe. He fled and another Tremere replaced him in the Council of Seven. Meerlinda arranged a meeting of Clan Elders in 1394 AD, at which the Ventrue Hardestadt proposed what came to be the Camarilla. Anarchs destroyed the Tzimisce Antediluvian, and brought about another meeting in 1450 AD.

This time Toreador Rafael de Corazon made a famous speech of the Fifth Rule of the Code of Caine, which led to the Masquerade and the Camarilla at last. Goratrix went over to the Sabbat. Structure of Clan TremereThe Clan is extremely hierarchical, and is oft described as a pyramid. At the head of the pyramid is Tremere. He is served by the Council of Seven, each of whom have seven Pontifexes of Orders under their command. Each Pontifex has seven Lords of Realms, and Each Lord has [in theory anyway] seven Chantry Regents. Below the Regents are the Apprentices. A Tremere must pass through seven levels of training, known as the Seven Circles of Mystery, and then wait for an opening before ascending to the next ranking