Iran’s supreme leader, Ayatollah Sayyed Ali Khamenei, recently underwent prostate surgery, following recurrent rumours that he suffers from some form of cancer. The looming succession in Iran is far from straightforward. In this article, Open Briefing contributing analyst Kevjn Lim considers the pool of candidates from which the Supreme Leader's successor may emerge, as well as the possibility of a temporary leadership council or even a Revolutionary Guards-led military takeover.