The Last Convocation was the final assembly held by tyrant, and confessed Umbra member, Judy Dorchester, a witch who had used her Wizengamot powers to overthrow Headmistress Hannah Fischer and seize control of the castle so that she could mould the students within it, into an army.
It was interrupted by Hannah Fischer, along with Oreyn Fox, Zimelda Zemeckis and Draco Romanov, where a large fight broke out, resulting in Dorchesters capture.