[2] While in school, he traveled to Italy several times with the aid of government grants to study classical civilization.

His dissertation, Die Komposition der Politik des Aristoteles, was supervised by Hans von Arnim.

Altheim received a scholarship from the Notgemeinschaft der Deutschen Wissenschaft in 1925, and gained his habilitation in 1928 with the thesis Griechische Götter im alten Rom, which was supervised by Walter F. Otto.

[3] This letter nearly prevented his appointment in 1936 as Associate Professor of Classical Philology at the University of Frankfurt.

With his partner Erika Trautmann, Altheim went on research expeditions to Italy, Sweden, Romania and the Middle East, during which he prepared reports for the Sicherheitsdienst.

His research centered on the history of classical antiquity, and many of his monographs on this subject were translated into other languages.

In 1950, Altheim was appointed Chair of Ancient History at the newly created Free University of Berlin.