The two leading thinkers in historical geography in the English-speaking world in the mid-20th century were Carl Sauer and H.C. Darby. Critical evaluations of the work of Carl Sauer have been published but so far none have examined the contribution of H.C. Darby, although the influence of his ideas on his students and many other contemporary scholars in geography, history and archaeology can be seen in the development of landscape studies and advances in the understanding of processes of geographical change.