The massacres of the 1450s changed the Institute at Cluj in Transylvania from a small mountain backwater to the busiest and most treacherous Nephilim posting in the world.
When Vlad III led a series of raids into Transylvania, vampirism spread through the entire region. The city of Cluj became the site of the first vampire clan officially recognized by the Clave, and Transylvania became the epicenter of the vampire epidemic.
In a stroke of historiographical luck, the Cluj Institute in the late fifteenth century was home to a Shadowhunter referred to as "Simion the Scribe" who provided a clear and detailed picture of the original spread of the vampire plague. A war between the Nephilim and the earliest vampire clans broke out. Shadowhunters, especially those already experienced at hunting Downworlders, traveled to Transylvania for the sole purpose of vampire slaying; new vampires continued to appear just as fast as old ones could be killed.
Within months the Cluj Institute, formerly one of the smallest and least important Institutes in Europe, had become the epicenter for the largest demonic epidemic the mundane world had ever seen. Chaos arose, as neither Nephilim nor vampires yet understood how new vampires were made or how they could be reliably killed.
The war ended with no clear winner. Knowledge of the vampiric disease grew, vampirism spread to other parts of Europe, and Shadowhunters returned home to sign treaties with local vampire clans and keep the peace in their own territories. Transylvania remained a devastated battleground for hundreds of years, where mortality rates for both vampires and Shadowhunters remained the highest in the world, and where the authority of the Clave was tenuous at best. Only with the unofficial end of the Schism in the first half of the eighteenth century did the battle die down.
Today, the Cluj Institute is, while more vampire-focused than most other Institutes, no busier or more dangerous than any other.
The Muzeul de Vampiri at the Institute re-creates the carnage of five hundred years ago through magically animated wax figures and became a frequently visited attraction among the Nephilim.
Large installations of witchlight are also found at the Cluj Institute, where the renowned Vampire Arch forms the threshold to the Institute. For many years it was thought that humans infected with vampirism were sensitive to natural and holy light and would recoil from it; the Arch was built under the belief that it would protect the Institute from infected humans. While this was eventually proven false, the Arch remains a symbol of the Cluj Institute's dedication to the Angel, and most likely a reminder of the tragedies that transpired years before.
- The Institute is also known as the "Cluj Institut".