Linda Partridge is the Weldon Professor of Biometry at UCL. She has made major contributions to understanding of ageing and life histories. Using the fruit fly Drosophila, she has identified genetic and environmental interventions that increase lifespan. Several of these also extend lifespan in yeast, the nematode worm C elegans and the mouse. Understanding the mechanisms at work is therefore likely to be of direct relevance to human ageing. Linda Partridge demonstrated that reduction of reproductive rate increases lifespan. Surprisingly, mating greatly increased female mortality. Experimental ablation of the accessory glands of the male demonstrated that molecules in the male accessory fluid were responsible. These molecules also increase egg-laying by the female. Using lines of flies artificially selected for increased lifespan, Partridge showed that egg-production causes a delayed wave of mortality. In male flies the cost of mating is mainly a cost of movement. Mutations in the insulin/IGF signalling (IIS) pathway were shown in the 1980s to extend adult lifespan in C. elegans. Partridge and her colleagues demonstrated that mutations in this pathway also extend lifespan in Drosophila and make the female flies sterile. She also demonstrated that dietary restriction extends lifespan in Drosophila. Most recently she has demonstrated that dietary restriction extends lifespan not by reducing the impact of irreversible, ageing-related damage, but rather through an acute reduction in short-term risk of death. The work has revealed the fundamental roles of nutrient-sensing and reproduction in causing ageing and death.