In July 1348, there was a terrible massacre in the Jewish quarter of Tàrrega. We know its scope from the documentation of the Royal Chancellery, the account of Josef ha-Kohen, The Valley of Tears, and the excavations in the mass graves carried out in 2007 at the Roquetes site. Both children and women, adults and the elderly died, and in that indiscriminate and furious attack, swords, axes, other types of bladed weapons and tools, and stones were used. The bone remains show extreme violence and atrocious beatings. For the first time, we also have the origin and composition of their DNA. A study by the Autonomous University of Barcelona (UAB)  promoted by the Department of Culture of the Generalitat de Catalunya, which has been published in Genes, has for the first time traced the genetic history of a medieval Jewish community in the Iberian Peninsula. Until now, none had been done for this community before their expulsion in 1492.