Upon his return to Europe in 1845, he married Elisabeth Klein in 1846 and was appointed as a professor of Egyptology at Berlin University in the same year, and the co-director of the Ägyptisches Museum in 1855; after the death of Giuseppe Passalacqua in 1865, he was director of the museum. In 1866 Lepsius returned to Egypt, where he discovered the Decree of Canopus at Tanis, an inscription closely related to the Rosetta Stone, which was likewise written in Egyptian (hieroglyphic and demotic) and Greek.