Part I of this paper describes a new 'Big Data' resource for historical mortality research, the Family History Society burials dataset. This comprises 8.9 million individual records harmonised from Family History Society transcriptions of burial records in 4,200 English places with varying coverage dates spanning from about 1500 to 2000, and concentrated in the period 1600 to 1850. Adult and child burials have been separately identified using family relationship information, and post-1812 more precise age information is stated. Part II presents an exploratory analysis of burial seasonality and age at death using the Family History Society burials dataset. The seasonality of birth and baptism, which impacts on infant burial seasonality, is also considered using a subsample of four English counties (Suffolk, Cambridgeshire, Nottinghamshire and Lancashire). This research forms part of a Wellcome Trust funded research project led by Richard Smith at CAMPOP entitled ‘Migration, Mortality and Medicalisation: investigating the long-run epidemiological consequences of urbanisation 1600-1945’.