The Appenzeller Jakob Künzler (1871-1949), who trained as a nurse in Basel, worked from 1899 to 1922 together with his wife in a mission hospital in the multi-ethnic Ottoman city of Urfa (present-day southeastern Turkey). Known as 'Brother Jakob' in the city, he was a very communicative person and spoke Turkish, Armenian, Arabic, and Kurdish, among other languages. Jakob Künzler's book from 1921 is one of the most important neutral eyewitness accounts of the Armenian tragedy during World War I. The author witnessed firsthand how the Young Turk war regime committed the first genocide of the 20th century. From the very beginning, he understood what the deportations and the elimination of insurgents meant. As a long-time medical professional in Urfa, he was recognized as an authority by the various groups, factions, and ethnicities. This enabled him to perceive the events, which are still portrayed inconsistently today, on different levels, including that of the local power holders. He wrote his harrowing account in clear, unvarnished language. The book, published in Germany in 1921, is long out of print and can only be found in a few libraries. This new edition makes this rare document accessible again to an interested audience and historical scholarship. An introduction with biographical information and historical explanations by the editor Hans-Lukas Kieser, as well as Künzler's reports from 1919-1921, complement this important contemporary witness account.