Depending on the criteria, between 8 and 34 autonomous polities that existed in the Middle East after WWI disappeared, either by being absorbed into or conquered by states. Some of these polities are remembered in residents’ collective memories, such as the Republic of the Rif (1921-26). Others, such as the Republic of Hatay (1938-39), appear to have been largely forgotten. This paper begins by describing, mapping, and categorizing this set of “failed states” – states or autonomous regions that existed after 1918 but are not recognized states today. It then matches and compares a sample of these polities to extant states to identify factors that might account for why some autonomous polities survived (e.g., The Emirate of Transjordan, later the Hashemite Kingdom of Jordan) and others (e.g., The Kingdom of the Hijaz, 1916-25) did not. I hypothesize that the interests of colonial powers is a key factor that accounts for why some polities survived while others did not but that such interests play little role in explaining why some failed states are remembered and others are not. The third part of the paper considers the extent to which “memories of state” remain in some of these places. This is an important question for the contemporary Middle East: for example, what is the likelihood and feasibility that one or more of the five separate states that existed in Syria under the French Mandate might (re-)emerge in the coming years? The paper concludes with an examination of the often-made claim that the borders and states of the Middle East are artificial and amenable colonial constructs.