A dataset of historical sediment Carbon and Nitrogen isotope measurements from lake cores (n=95) spanning the range of lake types and catchments found across the UK. These data have been obtained from the Environmental Change Research Centre (ECRC) lake sediment core archive with well-resolved time intervals (1850, 1900, 1980 and present) determined by radiometric dating (210Pb; 137Cs). This data has been collated to investigate historical sources and accumulation of C and N in lakes. This dataset provides historical data for hydrological / nutrient modelling from the Long Term Large Scale (LTLS) Project in the NERC Macronutrients programme. Full details about this dataset can be found at https://doi.org/10.5285/4b53b1d7-f290-4b47-97e9-9f9ec79f3003