History of Bithynia
The first record we have of roads in Bithynia is that described by Xenophon in the Anabasis, when 10,000 men marched along the Black Sea in about 400 BC. After Alexander the Great’s invasion of Asia Minor a local king, Nicomedes 1, founded Nicomedia. His sucessor, Nicomedes III left his kingdom to the Romans and Bithynia flourished until, in 270 AD, Nicomedia was chosen by Diocletian to become capital of the eastern Roman Empire.
Nicomedia’s period of glory was short-lived. In about 330, the government moved to Constantinople, and traffic patterns move accordingly. Constantine redirected trade from the south to his new capital of Constantinople across the gulf by ferry, without it having to go through Nicomedia.
Today, ancient Nicomedia is submerded beneath the waters of the gulf or the masses of new building which lines the shores. Part of the walls and theatre remain, and fragments of its past glory are unearthed whenever foundations are excavated, but very little remains.
Roads of Bithynia
The Byzantine road network in Bithynia was a continuation of the Roman one, but several new linking sections were developed to serve the enhanced Byzantine trade requirements. Under Diocletian, the main continuation of the Via Militaris or Via Diagonalis, coming from Belgrade, ran down the coast from Byzantion via Dacibyza / Gebze; it divided as it passed through Nicomedia.
The Diagonal / Pilgrim road went to Antioch and Jerusalem.
The Military road crossed North Anatolia to the frontiers.
The traffic carried down the coastal road from Chalcedon to Nicomedia must have been very heavy and was most likely supplemented by sea transport then bypassed by ferries. Additional roads, especially south of Nicomedia, became more important and were later used as the foundation roads of the Ottoman Empire. They were not made to the same standard as Roman roads – they were narrower, could be steeper and stepped, and generally had less paving or were paved with smaller stones.
Connecting with the crossing of the Bosphorus at Rumeli Feneri, a Roman road ran north towards the Black Sea then turned east towards the coastal town of Şile. Here it met a second road which crossed northern Bithynia to Nicomedia. We are researching the course of this road on the ground and hope to find more sections. There were once a large number of Roman bridges in this area which give valuable information avbout the course of the ancient roads.
By means of the connection Bosphorus – Şile – Iznik, we have a connection between the Sultans Trail and the Hosgörü road by means of Roman/Byzantine roads. It is unlikely that work on this road sytem will be complete for another two years but we are confident that the necessary link can be established.