Bordered by the Tagliamento in the west and the Isonzo in the east, the triangle of flatlands west of Trieste and south of Udine seems unpromising territory for a visitor – mile upon mile of maize fields, streams, market gardens and newish villages. Yet Aquileia was once the Roman capital of Friuli and is the most important archeological site in northern Italy. These unremarkable fields have yielded a wealth of Roman remains, while the glorious basilica here ranks among the most important monuments of early Christendom.
Some 45km west of Trieste, Aquileia was established as a Roman colony in 181 BC, its location at the eastern edge of the Venetian plain – on the bank of a navigable river a few kilometres from the sea – being ideal for defensive and trading purposes. It became the nexus for all Rome’s dealings with points east and north, and by 10 BC, when the Emperor Augustus received Herod the Great here, Aquileia was the fourth most important city in Italy, after Rome, Milan and Capua. In 314 AD the Patriarchate of Aquileia was founded, and under the first patriarch, Theodore, a great basilica was built. Sacked by Attila in 452 and again by the Lombards in 568, Aquileia lost the patriarchate to Grado, which was protected from invasion by its lagoons. Aquileia regained its primacy in the early eleventh century under Patriarch Poppo, who rebuilt the basilica and erected the campanile, a landmark for miles around. But regional power inevitably passed to Venice, and in 1751 Aquileia lost its patriarchate for the last time, to Udine. The sea has long since retreated, the River Natissa reduced to a reed-clogged stream, and Aquileia is now a quiet little town of 3500 people.