Thomas Edward Cliffe Leslie was one of the founders of British historical economics. He was an important figure in the history of economic thought of the nineteenth century, as he contributed to the critique of Ricardian political economy while at the same time being one of the founders of the British historical school. Cliffe Leslie was influenced by classical economists, such as Adam Smith and J. S. Mill, in calling for a historically and institutionally informed political economy. This article attempts to delineate the evolution of his economic thought by presenting the first phase of his intellectual development, which is marked by his frequent journeys in continental Europe. This phase, which is characterized by his applied political economy, is of considerable importance for understanding the emergence of British historical economics.