There is growing evidence demonstrating the importance of epigenetic signatures in health and disease. Research also suggests that epigenetic influences can act at different stages throughout the life course and show age-specific developmental patterns. However, a major obstacle in investigating the characteristics of this ‘life course methylome’ (i.e. a map of DNA methylation across all ages of the lifespan) has been the lack in data harmonization protocols for DNA methylation studies at different ages and the development of appropriate statistical approaches to draw different data sources together in order to analyse these changes in epigenetic patterns. The objective of this project is to synthesise such a life course methylome. With this map of variation in methylation across the life course, we can then identify those eras that show most variability as these may highlight critical windows for healthy development or disease vulnerability.