He participated in excavations on the island of Samos—joining his brother Franz, who had been working on the Heraion sanctuary—, building palaces and travelling in 1864 through Palestine, under order of the Ottoman Empire, drawing up accurate maps of the area.

His work as a surveyor for the railway and road construction departments helped him gain a personal familiarity with classical-era ruins, as well as develop an extensive network of contacts and acquaintances.

On the other hand, Humann established extensive connections throughout the whole of the Ottoman Empire, with local officials as well as workmen, which earned him the nickname “Viceroy of Asia Minor” and the very important esteem of the director of the Turkish Museums, Osman Hamdi Bey (Schulte, 1974).

Finally, in 1878, he received the backing from the director of the Berlin Sculpture Museum and financial support from Alexander Conze, as well as the official permits from the Ottoman government, to start excavations in September of the same year.

Back in the German Empire, the finding of the great altar, recognised to be one of the finest examples of Hellenistic sculpture, garnered significant attention and made Humann instantly famous.

On behalf of the Berlin Academy of Sciences, Humann later made recordings of the ancient archaeological sites of Angora, in both the upper Euphrates as well as northern Syria.