Sebald's works are largely concerned with the themes of memory and loss of memory (both personal and collective) and decay (of civilizations, traditions or physical objects). They are, in particular, attempts to reconcile himself with, and deal in literary terms with, the trauma of the Second World War and its effect on the German people. In "On the Natural History of Destruction" (1999), he wrote a major essay on the wartime bombing of German cities and the absence in German writing of any real response. His concern with the Holocaust is expressed in several books delicately tracing his own biographical connections with Jews.