Abstract: Why did England industrialize first? And why was Europe ahead of the rest of the world? Unified growth theory in the tradition of Galor and Weil (2000, American Economic Review, 89, 806-828) and Galor and Moav (2002, Quartely Journal of Economics, 177(4), 1133-1191) captures the key features of the transition from stagnation to growth over time. Yet we know remarkably little about why industrialization occurred much earlier in some parts of the world than in others. To answer this question, we present a probabilistic two-sector model where the initial escape from Malthusian constraints depends on the demographic regime, capital deepening and the use of more differentiated capital equipment. Weather-induced shocks to agricultural productivity cause changes in prices and quantities, and affect wages. In a standard model with capital externalities, these fluctuations interact with the demographic regime and affect the speed of growth. Our model is calibrated to match the main characteristics of the English economy in 1700 and the observed transition until 1850. We capture one of the key features of the British Industrial Revolution emphasized by economic historians slow growth of output and productivity. Fertility limitation is responsible for higher per capita incomes, and these in turn increase industrialization probabilities. The paper also explores the availability of nutrition for poorer segments of society. We examine the influence of redistributive institutions such as the Old Poor Law, and find they were not decisive in fostering industrialization. Simulations using parameter values for other countries show that Britains early escape was only partly due to chance. France could have moved out of agriculture and into manufacturing faster than Britain, but the probability was less than 25\%. Contrary to recent claims in the literature, 18th century China had only a minimal chance to escape from Malthusian constraints. Copyright Springer Science+Business