The ecosystem services provided by tropical coral reefs are worth over £65 billion annually and include tourism, fisheries and coast line protection. However, the health of tropical corals can be detrimentally impacted by stressful environmental conditions, which often lead to coral bleaching; that is, the loss of marine photosynthetic organisms (zooxanthellae: Symbiodinium sp.) which live within the corals themselves. Zooxanthellae provide the corals with extra energy allowing them to create massive reef structures. Ocean warming is the most significant bleaching trigger and is well documented in conjunction with major global bleaching events in 1998 and 2002, which caused widespread coral death. Importantly, climate projections suggest continued warming of the World’s oceans in the future, putting coral reefs and the services they provide at significant risk. Despite this threat, bleaching records currently only extend back ~50 years; they indicate increased coral bleaching in recent times but do not put recent events into a longer temporal context. In this project, we will reconstruct historic coral bleaching using growth records trapped within coral skeletons. These will tell us if recent bleaching trends represent natural variability or a sudden acceleration in response to rapid warming allowing us to understand the mechanisms behind past coral survival. Critically, this will enable us to assess the future survival trajectories for coral reefs in warmer oceans.