This volume continues the publication in Spanish of all of Franz Kafka's letters that have been preserved. Letters here are understood to mean all the letters written by Kafka throughout his life, whether postcards, telegrams or letters themselves, without excluding those of an official, commercial or professional nature. Nearly two hundred of the letters collected here had never before been translated into Spanish. But equally or more remarkable than the novelty that this represents is the fact that all the letters are given in a new translation made from the text and the chronological sequence established by the very demanding German critical edition by Hans-Gerd Koch. They are served accompanied by notes and reference tools that allow them to be understood and enjoyed in all their scope. The years that comprise the letters collected here (1914-1920) belong to Kafka's maturity. This is a decisive period in the writer's life, a good part of which takes place under the impact of the First World War, which broke out on July 28, 1914, two days after the date of the last of the letters collected in the volume I.