Servatius was born in Cologne on 31 October 1894. In the First World War he served as an artillery officer, and during the Second World War returned to military service, rising to the rank of Major. He was never a member of the Nazi Party, and was never connected with any of its crimes. At the Nuremberg Trials he served as a criminal defense lawyer.
A number of lawyers had offered to appear for his defense, and Eichmann chose Servatius. As a result, the Israeli law had to be changed to enable this, as until that time foreign lawyers had no right of audience in the Israeli courts. The change made enabled only those facing a capital charge to be represented by a non-Israeli lawyer. Before he was appointed to defend Eichmann, Mossad investigated the history of Servatius, but they found nothing which greatly troubled them. Although hired by Eichmann, Servatius was paid by the Israeli government, following a precedent set at Nuremberg. He was assisted in the defense of Eichmann by Dieter Wechtenbruch.
- Dan Diner, Raphael Gross, Yfaat Weiss, Jüdische Geschichte als Allgemeine Geschichte (2006), p. 218: "geboren am 31. Oktober 1894 in Köln, war im Ersten Weltkrieg Artillerieoffizier gewesen und hatte am Ende des Zweiten Weltkrieges den Rang eines Majors erreicht. Da er nie der NSDAP angehort hatte oder von den Alliierten in irgendeiner Weise mit NS-Verbrechen in direkten Zusammenhang gebracht worden war, wurde er in Nuernberg als Strafverteidiger zugelassen."
- Jonathan D. Moreno, Undue risk: secret state experiments on humans (2001), p. 63: "Robert Servatius of Cologne... represented Fritz Sauckel in the major Nuremberg trial of Nazi political leaders a few months before the doctors' trial."
- Steven Lehrer, Wannsee house and the Holocaust (2000), p. 174: "Dr. Robert Servatius was Eichmann's German attorney."
- The Israel digest of press and events in Israel and the Middle East, vols. 4-5 (1961), p. 57
- Alexander Laban Hinton, Genocide: an anthropological reader (2002), p. 91
- The Israel digest of press and events in Israel and the Middle East, vols. 4-5 (1961), p. 205