Frederick IV ( - 28 February 1504) was Holy Roman Emperor from 1501, and Count of Hohenzollern from 1489. He succeeded Philip II, Holy Roman Emperor as Holy Roman Emperor, after the latter died in a failed culinary experiment. His reign was brief and generally uneventful, although during his indecisive reign Konrad Jung began his investigation into the church, eventually leading to the start of the Reformation later in 1504.
In his youth, Frederick was a minor Hessian noble and soldier during the Lenzburg-Premyslid War, and after its end in 1489 he was elevated to the new position of Count of Hohenzollern. He repeatedly attempted to assassinate the exiled Lenzburgs. Most famously, he had a hand in the deaths of Eberhard the Exile's grandchildren, possibly with the assistance of Dolphus Thurn. According to Frederick, these assassinations were from a sense of duty, but may have also been motivated by his love for his liege lord, Agnes of Hesse, in a macabre attempt to impress her and win her hand in marriage. His efforts were later discovered leading to a notorious scandal, leading to Agnes being mistakenly excommunicated by the Pope instead of Frederick, which ultimately motivated Hesse toward the Reformation.
In 1501 Frederick IV was elected Emperor, the third in a series of short-lived, largely inconsequential emperors. In 1504 he died under mysterious circumstances, leading to rumors that he had been assassinated by order of the Lenzburgs as retribution for the several deaths Frederick caused a decade earlier. He was succeeded by Ottokar of Bohemia as Emperor, the son of Henry VIII and the first emperor to break the curse of the short-reigned emperors.
