Shadowhunters, also known as Nephilim, are a secretive race of beings who are humans born with angel blood.
They have fought demons and lived alongside Downworlders in the Shadow World for well over a thousand years, creating their own culture and civilization within human society.
While Sebastian was ultimately defeated, it was too late as a large majority of the Shadowhunters gathered at Alicante had already been slaughtered.
To salvage their population and ranks, the Clave decided to reopen the Academy and recruit more mundanes for Ascension.
A warlock summoned the Angel Raziel, who mixed some of his own blood with the blood of men in a cup, and gave it to those men to drink.
They advocated and upheld their belief that they must increase their numbers by turning more mundanes with the Mortal Cup, and that they must once again be united and up in arms primarily against Downworlders.
During the signing, they planned to slaughter the attending unarmed Downworlders, as well as the Shadowhunters who would resist and defend the Downworlders.
While there have been women fighters over the years, and it is recognized that there have always been women in the Clave—mastering the runes, creating weaponry, teaching the Killing Arts—but only a few were warriors, ones with exceptional abilities who had to fight to be trained.
It was a generation in the late 1900s, which included Maryse Lightwood and Jocelyn Fray, that was the first where all women were trained to become Shadowhunter warriors along with the men.