For 10 points, name this fourteenth century event that likely killed at least a third of Europe's population through the bubonic plague.
A faculty in Paris wrote in a Compendium that this event was caused by Saturn, Jupiter, and Mars all being in conjunction in the House of Aquarius. The Annals of John Clynn ends with his description of this event, which possibly resulted in Clynn's death. Although he never left Piacenza, Gabriel de Mussis described the beginning of this event and was initially mistaken for an eyewitness of it in Sicily and Kaffa. During a siege of Gibraltar, Alfonso XI of Castile became the only monarch to be killed by this event. This event's spread was blamed on trade ships from Genoa, which helped transport the bacteria Yersinia pestis. For 10 points, name this fourteenth century event that likely killed at least a third of Europe's population through the bubonic plague.
A faculty in Paris wrote in a Compendium that this event was caused by Saturn, Jupiter, and Mars all being in conjunction in the House of Aquarius.
Black Death [prompt on bubonic plague]