Over fifty years ago, the 1,2‐rearrangement of acylsilanes was first described by Adrian Brook and co‐workers. This rearrangement (now termed the Brook rearrangement) yields reactive silicon‐based singlet nucleophilic carbene (SNC) intermediates that participate in a variety of chemical transformations including 1,2‐carbonyl addition, 1,4‐addition to electron‐deficient unsaturated bonds and insertion into C−H and O−H bonds. This review aims to cover the historical literature and recent advances with regard to these valuable silicon‐based reagents and highlight additional aspects related to the intriguing reactivity of both the carbene and oxocarbenium intermediates.