The most dev­as­tat­ing attacks against the Jews of medieval Chris­t­ian Europe took place dur­ing the riots that erupt­ed, in 1391 and 1392, in the lands of Castile and Aragon. For ten hor­rif­ic months, hun­dreds if not thou­sands of Jews were killed, numer­ous Jew­ish insti­tu­tions destroyed, and many Jews forcibly con­vert­ed to Chris­tian­i­ty. Ben­jamin Gam­pel explores why the famed con­viven­cia of medieval Iber­ian soci­ety — in which Chris­tians, Mus­lims and Jews seem­ing­ly lived togeth­er in rel­a­tive har­mo­ny — was con­spic­u­ous­ly absent. Using exten­sive archival evi­dence, this crit­i­cal vol­ume explores the social, reli­gious, polit­i­cal, and eco­nom­ic ten­sions at play in each affect­ed town. The rela­tion­ships, biogra­phies and per­son­al dis­po­si­tions of the roy­al fam­i­ly are explored to under­stand why monar­chic author­i­ty failed to pro­tect the Jews dur­ing these vio­lent months. Gam­pel’s exten­sive study is essen­tial for schol­ars and grad­u­ate stu­dents of medieval Iber­ian and Jew­ish history.