Lars Åke Persson has been professor of Public Health Evaluation at the London School of Hygiene & Tropical Medicine since 2016 and is based at the Ethiopian Public Health Institute, Addis Ababa, Ethiopia, leading the Dagu project. He has worked in different African and Asian countries, been director of Public Health Sciences at icddr,b in Bangladesh, and professor of Global Child Health at Uppsala University, Sweden. His research toolbox includes epidemiology, community-based trials, as well as implementation science designs. In his inaugural lecture, he will give examples from research that saved lives, influenced policy and practice, or generated new questions. What can we learn from revisiting the child survival revolutions in selected African, Asian and Latin American countries? Can prenatal nutrition interventions save infant lives and favourably change child growth and metabolic trajectories? Can engaged communities reduce neonatal mortality? Is it possible to combine front-line research with capacity building and Ph.D. training? And what about the crocodile?