Catapults have been integral to siege warfare since antiquity. Though ancient Catapults were one of the most effective weapons in siege warfare. Various types of Catapults have been used by the Greeks, Romans, and Chinese. The first catapults were early attempts to increase the range and power of a crossbow. Diodorus Siculus, a Greek historian, was the first to document the use of a mechanical arrow firing catapult (early Ballista) in 399 BC. Catapults as we think of them were introduced to Europe during the Middle Ages. Catapults made their exhibition in England in 1216 during the Siege of Dover, the French crossed the Channel and were the first to use Catapults on English soil. With war prevalent throughout Europe during the Middle Ages the popularity of fortified castle and city wall rose significantly. This made Catapults an essential. Catapults were used to launch missiles (many different objects were utilized). These missiles were either launched directly at the wall to cause maximum damage to the fortifications or were launched over the wall to lay siege on the population within the protective walls. Catapults were also used to throw missiles at soldiers. The first accounted acts of Biological Warfare involved catapults. Bodies of the diseased were hurled over the city walls to infect the residing citizens. Catapults were used extensively throughout Europe (predominantly by the French) until 885-886 AD when new defense systems rendered catapults ineffective.