The first, the Plague of Justinian, struck the Old Continent between 541 and 542, when it arrived in Constantinople from Egypt or Ethiopia. From there it spread throughout Europe reaching Danish territory. Although the exact number of dead cannot be determined, it is estimated that the Justinianic plague killed 50 million people. The plague returned every dozen to several decades, and the last time it occurred on a large scale was around 750. The second plague was the Black Death, also caused by Yersinia pestis, which decimated the population of Europe between 1346 and 1353, killing between 75 and 200 million people.
