The surgical management of sinonasal disease has evolved significantly over the past century, reflecting advances in anatomical understanding, optical technology, and surgical philosophy. Early sinus surgery in the late nineteenth and early twentieth centuries was characterised by external and radical procedures, including the Caldwell-Luc operation and external ethmoidectomy, aimed at wide drainage but associated with significant morbidity. A paradigm shift occurred in the latter half of the twentieth century with improved understanding of mucociliary clearance and the central role of the osteomeatal complex in chronic rhinosinusitis. Building on this concept, Messerklinger’s work on endoscopic visualisation of sinus drainage pathways laid the foundation for functional endoscopic sinus surgery (FESS). The introduction of rigid endoscopes, fibreoptic illumination, and high-resolution imaging enabled precise, minimally invasive surgery focused on restoring physiological ventilation and drainage rather than radical mucosal removal. Since its adoption in the 1980s, FESS has become the cornerstone of modern sinus surgery, with ongoing refinements including image-guided navigation, powered instrumentation, and extended endoscopic approaches to the skull base and orbit. This historical overview highlights how evolving scientific insight and technology transformed sinus surgery into a functional, anatomy-driven discipline central to current ENT practice.