This edition of Epilepsia marks the 100th anniversary of the journal, the first issue of which was published in March 1909. The ILAE also celebrates its centenary on August 30, 2009, being founded on that date in 1909 in Budapest during the 16th International Medical Congress. At the same meeting, on September 3, 1909, Epilepsia was formally named as the official organ of the ILAE. For both the journal and the League to reach this landmark is a remarkable achievement. To mark the occasion, the current executive of the ILAE decided to document its history in the form of a book. Initially, the book was intended to cover both the ILAE history and the history of epilepsy over the 100-year period. As the project proceeded, however, it became clear that the book was growing too large and deadlines were being missed in the epilepsy section. For these reasons, in mid-2008 a decision was made to divide the history into two parts. It was determined that the book (Shorvon et al., 2009) would focus on a comprehensive history of the ILAE, and that a supplement of Epilepsia should be produced which dealt with aspects of the history of epilepsy. The supplement would be published on the journal’s 100th anniversary, and the book would be launched at the ILAE centenary conference in Budapest in June 2009.

This, then, is the origin of the present supplement, the articles within which provide an outline history of 10 different aspects of epilepsy during this period.

The history of epilepsy in the twentieth century is a challenging topic, as both the clinical and scientific elements have evolved greatly over this time. This supplement cannot be comprehensive, but aims to provide an impressionistic overview of the subject.

The articles emphasize the role of the ILAE and of Epilepsia, reflecting the crucial importance of both in the development of clinical practice and scientific work in epilepsy. This supplement should be read in conjunction with the book, as the history of epilepsy and of the ILAE in this period are closely intertwined.

History is memory, and a memory of past events is vital for all who look forward to the future. Memory provides perspective and promotes wise decision making, but it also fades fast. At a time when remarkable changes are under way in the clinical and basic research aspects of epilepsy, the importance of its history increases. We hope that in documenting parts of the story of our subject over the last 100 years, this small contribution will assist in providing perspective and improving the quality of our future work, and will be of interest to the readers of our journal.