In Memoriam: Mark Hallett (1943–2025)

The passing of Mark Hallett has left our field all the poorer.Mark was a giant in Movement Disorders who touched the lives of so many people in many ways.The wonderful tribute by Joe Jankovic and Günther Deuschl describes Mark's stellar career, highlights some of his many contributions, and gives an insight into his many interests and personality.1 In this article, we gather reflections from Mark's fellow Past Presidents (Fig. 1) of the International Parkinson and Movement Disorder Society (MDS) and other colleagues who knew Mark well, since they provide a further window into the great man that he was. David Burn (Galway, Ireland)I first "met" Mark at an American Academy of Neurology teaching course in Boston in 1991 while working for David Brooks as a research fellow.There was some noise in between lectures, and Mark stepped up to the microphone with a loud "Boo!" that led some attendees to jump with surprise.It was, of course, a lecture on myoclonus.The last time I saw Mark was in Philadelphia, in 2024, at a Past-President's dinner, when he was accompanied by his wife Judy.He was on sparkling form, having recovered from injuries sustained in a nasty fall a few months before.Neither of us could have predicted at that time the diagnosis that would be made only a few short months later.It was always clear to me the high regard in which Mark was held by our Society, his kindness to everyone, and his humility.