Promotion of EBF is the most effective child health intervention currently feasible for implementation at the population level in low-income countries. It can lower infant mortality by 13%, and by an additional 2% were it not for the fact that breastfeeding transmits HIV. Only recently proven to be possible in hot and even dry climates, EBF without even offering water is still little appreciated by mothers or supported by health workers. EBF rates are especially low in Africa but the potential for rapid implementation may be high. A few studies elsewhere suggest that peer counselling can often achieve dramatic increases. Thus the investigators will run the first randomised trial to develop and test models for applying this approach in four African countries and to quantify health benefits, cost-effectiveness, and implications for the health care system.