In his A History of Macedonia, Nicholas Hammond reconstructed the earliest phases of Macedonian history based on his interpretation of later literary accounts and archaeological excavations in the region of Macedonia. According to Hammond, the Macedonians are missing from early Macedonian historical accounts because they had been living in the Orestian highlands since before the Greek Dark Ages, possibly having originated from the same (proto-Greek) population pool that produced other Greek peoples. The Macedonian tribes subsequently moved down from Orestis in the upper Haliacmon to the Pierian highlands in the lower Haliacmon because of pressure from the Molossians, a related tribe who had migrated to Orestis from Pelagonia. In their new Pierian home north of Olympus, the Macedonian tribes mingled with the proto-Dorians. This might account for traditions which placed the eponymous founder, Makedon, near Pieria and Olympus. Some traditions placed the Dorian homeland in the Pindus mountain range in western Thessaly, whilst Herodotus pushed this further north to the Macedonian Pindus and claimed that the Greeks were referred to as Makednon (Mακεδνόν) and then as Dorians. A different, southern homeland theory also exists in traditional historiography. Arnold J. Toynbee asserted that the Makedones migrated north to Macedonia from central Greece, placing the Dorian homeland in Phthiotis and citing the traditions of fraternity between Makedon and Magnes.