In a book published in 1919, Ludwig Deppe, a doctor of medicine who campaigned with Lettow-Vorbeck and who had formerly headed the hospital at Tanga, lamented the tragedy that German forces had imposed on East Africa in their war with the Allies: "Behind us we leave destroyed fields, ransacked magazines and, for the immediate future, starvation. We are no longer the agents of culture, our track is marked by death, plundered and evacuated villages, just like the progress of our own and enemy armies in the Thirty Years' War." When the worldwide Spanish influenza epidemic swept into eastern Africa in 1918–1919, it struck down thousands of people. The weakened state of many native Africans, resulting from the war, made them especially susceptible.