The city went through serious troubles in the mid-fourteenth century. On the one hand were the decimation of the population by the Black Death of 1348 and subsequent years of epidemics — and on the other, the series of wars and riots that followed. Among these were the War of the Union, a citizen revolt against the excesses of the monarchy, led by Valencia as the capital of the kingdom — and the war with Castile, which forced the hurried raising of a new wall to resist Castilian attacks in 1363 and 1364. In these years the coexistence of the three communities that occupied the city—Christian, Jewish and Muslim — was quite contentious. The Jews who occupied the area around the waterfront had progressed economically and socially, and their quarter gradually expanded its boundaries at the expense of neighbouring parishes. Meanwhile, Muslims who remained in the city after the conquest were entrenched in a Moorish neighbourhood next to the present-day market Mosen Sorel. In 1391 an uncontrolled mob attacked the Jewish quarter, causing its virtual disappearance and leading to the forced conversion of its surviving members to Christianity. The Muslim quarter was attacked during a similar tumult among the populace in 1456, but the consequences were minor.

When did Valencia suffer from the Black Death?