Kafka’s circle of friends was small and had essentially been formed during his early years; at elementary school (Hugo Bergmann), high school (Oskar Pollak and Ewald Felix Příbram) and university. This particularly applies to the four closest friends whom Max Brod dubbed ‘The Prague Circle’: Kafka, Max Brod, Oskar Baum and Felix Weltsch.
In later years when Franz Kafka became increasingly self-absorbed, it became more and more difficult for him to make friends and existing friendships grew weaker. This is illustrated by his relationship with Ernst Weiss, for instance. The exception was his short-lived but intense friendship with the Jewish actor Yitzhak Levi and the relationships formed in the shadow of his illness within the narrow confines of sanatoria, such as with Minze Eisner and particularly with the doctor Robert Klopstock.