With the passing of the centuries, only "Centocelle" resisted the silting up and the destruction which caused the other ports to disappear and so it assumed the function of port for Rome.
During the Empire, the barbarian dominations, and, afterwards, under the dominium or the popes, it became always more of a military and commercial port as opposed to appassenger port or port for shelter.

In the height of the Middle Ages, after the return of the refugees to Centocelle, it regained life so much so that in the 10th century it was the greatest port of Tyrrhene.
The internal calm of the Papal State which was gained with the popes of the 4th Century made its benefits felt on the port and the great works ordered by Sisto IV allowed new traffic developments.
In the following century the port became one of the principle military bases against the Turks and in the 6th century it was able to compete with Livorno and Genoa.
Afterwards the reactivation of Fiumicino and Anzio diminished the level of traffic, but following that, in the last century, after the unification the reclaimed land was significantly enlarged, favoured by railways, new roads ad industrial development ad the port assumed the phisonomy ad characteristics which it still has today.

The original appearance of the dock was one of an almost circular mirror of water, with ½ km diameter protected by two solid jetties stretching out into the sea for 400 m. In the internal part by the west breackwater a minor dock was then constructed, the future "Roman Harbour".
The first remodernizatonwas carried out in 1508 by Julius II, who began the fortress (the future "Michelangelo Fort") ; in 1513 Leo X ordered the total restoration of the Roman harbour ; in 1592 Clement VIII ordered the restoration of the break-waterwich was protected by large rock Jetties.
In the early hears of the following century, large warehouses were constructed under Paul V, whilst Urban VIII had the Jetties reinforced, the Trajan breackwater lengthened and the bottom basin dug out.
Again in the 6th century, the Great Bernini Arsenal Arose a most characteristic monument which was destroyed during the last war, and which occupied approximately the area where the office of the harbour master now stands.

The arsenal, situated at short distance from the Fortress, was built in 1660 under the Papa rule of Alexander VII.
It was 50 metres long and consisted of 6 large alleys, each one capable of hosting a gallery under construction.
The aisles were coupled in pairs and each pair was placed on three beams which converged in the sea where, with a slight slope, there was the exit in one of the three sides of the hexagon wich formed the beautiful prospect, covered in travertine and decorated with the great marble coat of arms of Alexander VII surmounted inthe centre.

After the unification, the east mouth was closed and the maritime station was built, burying one part of the underwater dock. The breakwater was lenghtened and new jetties, silos and warehouses were created.

The destruction from the last war was extremely serious considering that 80% of the complex was devestated. The reconstruction which was begun immediately, returned the port to its former efficiency which becomes even greater with the creation of new docks and jetties.