This article addresses the history of European colonialism during the age of imperialism in the late 19th and early 20th century from a transimperial perspective. It starts with the assumption that colonial history is all too often written along national lines that offer a limited perspective on events and circumstances. By contrast, this study emphasizes instances of exchange and mutual aid between two colonial powers, Germany and Italy, which shared a degree of inexperience in the conquest of overseas territories. The two countries did not experience the start of the construction of their respective colonial empires exclusively as a moment of competition, but also of mutual support in the face of similar dangers and common uncertainties. Among the many areas of analysis, the article focuses on the mobility of soldiers and the awarding of decorations across colonial borders, the diplomatic and scientific visits between the two imperial contexts, and the network of scholarly exchanges on different aspects of colonial governance. Further avenues of research may concern other areas of exchange and aid, as well as other empires.