The history of the treatment ofbrain tumours in the Netherlands begins around 1890. From this time up to 1950, following other European countries and later the United States, the conceptualization, diagnostics, and surgical treatment of brain tumours changed dramatically. New morphological classifications were introduced, as well as technical innovations in the fields ofimaging diagnostics and surgical methods. At the same time, the common view ofclinical signs ofbrain tumours changed into the concept that symptoms were caused by increased intracranial pressure. As is the case today, the innovations in Dutch neurosurgery in the first half of the 20th century were based on the interaction between techniques, knowledge and clinical experiences.