The main literary sources for the construction of the road are
Strabo's
Geographica and a number of
milestones found along the route's length, marking the road for a length of 860 kilometres as far as the border between Macedonia and Thrace. Bilingual inscriptions on the milestones record that
Gnaeus Egnatius,
proconsul of Macedonia, ordered its construction, though the exact date is uncertain; the road presumably took its name from its builder. It may have succeeded an earlier military road from Illyria to Byzantium, as described by
Polybius and
Cicero, which the Romans apparently built over and/or improved. The Via Egnatia was constructed in order to link a chain of Roman colonies stretching from the
Adriatic Sea to the
Bosphorus. The termini of the Via Egnatia and the
Via Appia, leading from Rome itself, were almost directly opposite each other on the east and west shores of the
Adriatic Sea. The route, thus gave the colonies of the southern Balkans a direct connection to Rome. It was also a vital link to Roman territories further to the east; until a more northerly route across Illyria was opened under
Augustus it was Rome's main link with her empire in the eastern Mediterranean. It was repaired and expanded several times but experienced lengthy periods of neglect due to Rome's civil wars. The road was used by the
Apostle Paul on his
second missionary journey as he traveled from
Philippi to
Thessalonica (
Acts 16–17). It also played a vital role in several key moments in Roman history: the armies of
Julius Caesar and
Pompey marched along the Via Egnatia during
Caesar's civil war, and during the
Liberators' civil war Mark Antony and
Octavian pursued
Cassius and
Brutus along the Via Egnatia to their fateful meeting at the
Battle of Philippi. Surviving milestones record that the emperor
Trajan undertook extensive repairs of the road prior to his campaign of 113 against the
Parthians. However, by the 5th century AD the road had largely fallen into disuse as a result of violent instability in the region. In later years, the Via Egnatia was revived as a key road of the
Eastern Roman Empire;
Procopius records repairs made by Eastern Roman emperor
Justinian I during the 6th century, though even then the dilapidated road was said to be virtually unusable during wet weather. Almost all Byzantine overland trade with western Europe traveled along the Via Egnatia. During the
Crusades, armies traveling to the east by land followed the road to Constantinople before crossing into
Asia Minor. In the aftermath of the
Fourth Crusade, control of the road was vital for the survival of the
Latin Empire as well as the Byzantine successor states the
Empire of Nicaea and the
Despotate of Epirus. ==Post-Roman usage==