The Uprising was a demonstration by the Circle, led by Valentine Morgenstern, against the Clave and Downworlders during the signing of the Ninth Accords in Alicante in 1991. The confrontation led to a fight that resulted in bloodshed, though its effects were thwarted and limited because of the efforts of Valentine's wife, Jocelyn, and former parabatai, Lucian.
Some time before the signing of the Ninth Accords in 1991, Valentine Morgenstern had made it clear that he was against the signing of the peace treaty between the Nephilim and Downworlders. When the Clave did not heed his words, Valentine and the Circle began plotting an Uprising against them. They planned to disrupt the signing of the Accords, killing all the Downworlders and Shadowhunters who went against them while they were all unarmed and defenseless in the Accords Hall. Valentine hoped that this would once again ignite a war between the Downworlders and Shadowhunters—one that they intended to win and hoped would lead to the eradication of Downworlders, whom some of the Circle's members saw only as part-demons and demonic beings inferior to them. Valentine had also wanted to kill any members of the Clave who would go against them and might get in the way of their ultimate goal, which was to somehow restart their race and purge the world of Downworlders, and eventually demons.
However, Valentine did not know that Jocelyn and Lucian had prepared the Downworlders who attended and others to come to their aid. Since weapons were not allowed in the Great Hall, Valentine and the Circle were the only ones armed with the weapons they smuggled in, which they were able to because of some alliance with demons. In the midst of the chaos that broke out, Jocelyn opened the gates for the Downworlders lying in wait.
The Uprising ended in bloodshed and massacre. The members of the Circle who did not leave before the Uprising faced trial and punishment; while others were given leniency, some were punished more severely than others, though most lived.
For years after that, the Uprising became a horrible part of Nephilim history, a painful reminder of the Circle's actions and Valentine's extreme ways. Nonetheless, while the general idea of the Uprising and Valentine's followers is known by most Shadowhunters, the Circle and the specifics of the event are mostly unknown, specifically among the younger generations, because the Clave had tried to rid their history of this embarrassment, destroying most documents pertaining to them in the process.