He took part in the excavations at Olympia in 1878, became an assistant in the Berlin Museum in 1880, and professor at Berlin (1884) and later at Munich.
Excavations were made on its site in 1811 by Baron Haller von Hallerstein and the English architect C. R.
Excavations on the site of Ostia were only begun towards the close of the 18th century, and no systematic work was done until 1854, when under Pius IX.
Numerous objects had been discovered in the course of excavations, but not one of them could be recognized as more than a few centuries old, while those that were not demonstrably foreign imports were of African type.
It concluded an alliance with Rome in 308 B.C. The modern village lies higher than the ancient town, and excavations on the site of the latter in 1775 and following years led to the discovery of the baths, a theatre, a basilica and other buildings.