There are twelve current Hermetic Houses, 11 of which follow the traditions of one of the Order’s Founding Wizards. The twelfth House replaced a fallen house and was originally a rival organisation. It has since become an umbrella house for disparate magical groups and traditions that wish to join the order. In the Theban tribunal there are those who believe that the number 12 is significant, symbolically linking the founders to the Olympian gods. Specific details of the houses are of course in the various Ars Magica books, the pages below deal with the Houses’ relations in the Theban Tribunal.