Dobruja`s history was largely determined by its geographical position being situated at crossroads. The main crossing routes for Dobruja are the sea route, the Danube`s route and the road that crossed the territory from north to south through its center.

Although, the Romans reached the Danube since 14 AD., only during the time of Emperor Domitian Dobruja was included in the empire`s strategic plans, Scythia Minor becoming a base for the expeditions against the Dacians over the Danube.

However, Traian is the one that manages sustainable organization of the Scythian limes, building forts and castles on the right bank of the Danube and at the crossing points, as is the case of Capidava city. With rare exceptions, the Scythian limes organized like this has assured peace of the province for more than a century.

Capidava city is located on the right bank of the Danube, at half the distance between Harsova (Carsium) and Cernavoda (Axiopolis), and it was built with the help of Vth Macedonica legion from Troesmis and XIth Claudia legion from Durostorum at the beginning of the IInd century. Besides Capidava, as a part of the fortifications made by Traian on the Danube`s bank we also mention Carsium (Harsova), Cius, Troesmis, Noviodunum and Aegyssus.

The toponym of the citadel is of Getae origin and means “settlement from around the corner”, thus, along with archaeological evidence, a pre-Roman inhabitation place was attested in this strategically important place for contacts between the Getae from Dobruja and the ones from the Romanian Plain. The toponym, which was preserved even to this day, is certified not only by ancient and then Byzantine sources but also with three inscriptions: C. Julius Qadratus`s tombstone from the IInd century, discovered at Ulmetum; a votive altar dedicated by Aurelius Valens to Hero, a Thracian deity; discovered at Ulmetum, too, and dated the late IIIrd century – early IVth century. The third one is a fragmented funerary inscription discovered recently at Capidava and belongs to Aurelius the military leader of the unit stationed in this fortress.

The place chosen for the construction of the fortification is particularly important in strategic terms, since this is a rocky mountain, surrounded by water on three sides (Danube) and a natural channel, which determined the installing of military station and the development of a civil center alongside. The rocky mountain`s shape where the citadel is found imposed the quadrangle plan of the fort.

The fortification for the Capidava auxiliary unit (castellum) was probably built in the period of the two offensive Dacian-Roman wars. The fortification was fitted with a port facility, a water pier, warehouses and other outbuildings and baths outside the citadel walls. Still, out of the city it is attested the tumulus cemetery with cremation graves, with high inventories, but also a flat necropolis with more modest funeral inventories.

Capidava, like other cities located at the border, had to face numerous attacks of the barbarian populations. Thus, the first Roman fort was destroyed by Carpo-Goths, probably after their invasion from the year 248, and it was completely rebuilt in the late III rd century, purely with defensive purpose. The ruins we see today have, as already mentioned, a rectangular plan, with sides of 105x127m, 2 m thick and 5-6m high walls, with seven towers over 10 m high (three rectangular towers, two as a quadrant and two intermmediate of horseshoe shape – U shaped). The citadel had a gate of approximately 2.5 m wide, situated on the South-Eastern side, which connected a strategic gate on the South-Western side of the tower towards the Danube and a port arranged in terraces toward the river with the rest of the territory.

The citadel suffered repeated damages until the fifth century being restored twice, because of the numerous attacks that have succeeded over decades. During the second restoration, capitals, architraves, statues of various deities, worship or burial reliefs are included into the walls. On one hand, this suggests a high urban level, on the other hand, considering that the parts came from the nearby civil settlement or necropolis prove that the repairs had been performed in a hurry.

In the VI th century, after the devastating attack of the Huns that scorched the city, it is likely that it no longer had sufficient funds for the reconstruction. In this situation, a small quadrilateral fort was built (60x60m) in the southern part of the citadel.

Because of the Slavic and Avar attacks, the city is completely destroyed and abandoned in the seventh century, including the last remaining troops that were watching that area.

In the ninth century, the Byzantine Empire`s borders were reorganized and Capidava, by its position, takes a role in the new defensive system`s organizational strategy. Therefore, over the ruins of the Roman fort, a stratiotai peasent fortress was built (peasants as border guards), which lasted until mid-eleventh century, also having been performed multiple repairs. The fortress was surrounded by a wall made of stone and soil that was going along the Roman-Byzantine precinct, doubled by a defense moat.

Being a military base, there were stationed a number of troops over time, epigraphically certified. At first, there is mentioned cohors I Ubiorum (secondary unit from Germany), stationed here from setting up its camp until 143. Cohors I Germanorum were next, another German unit stationed in the IInd and probably the IIIrd century AD. Later in the Roman-Byzantine era (IVth-VIIth centuries), a vexillatio Capidavensis (a detachment of the IInd Herculia Legion), cuneus equitum Solensium and cuneus equitum scutariorum are attested.

The precinct wall, the horseshoe - shaped intermediate towers and the citadel`s gate guarded by the tower are included in the visiting circuit. Public baths (thermae) were next which were built outside first castra`s precint, in order to be used by the auxiliary unit camped here. Several rooms with hypocaust, cold water basins, pools and water draining channel were identified.

The Basilica, the only one discovered so far, has three naves separated by two rows of pillars and ends with a semicircular apse. The Basilica dates from the first half of the VIth century and shows influence of the Syro-Palestinian religious architecture. It was overlayed on a smaller basilica, built in the late fourth century. In the VIth century, Capidava operated one of the episcopal centers of Scythia province, the strategic position held by Capidava within the area probably facilitated spreading Christianity. The latest excavation campaigns have revealed a new tower that, however, cannot be visited in order to be preserved. In the year 2015, extramuros research were conducted in the port area, and in 2017 is expected that the termae investigations are completed.

The housing units dating from the early medieval period have been investigated over a large area of the citadel. They show several levels of living as a result of successive repainting. A particularly important piece for the local history is a pitcher dating from Xth century and it had the Greek inscription of the Romanian name "Petre" (Peter). This piece, along with others from the same period illustrates the completion phase of the Romanian people.

There is information about the existence of a fortress here since the modern period, the name of the Turkish village founded in the XVIIIth century under the name of "Kale-köy" (the village of the citadel). The fortress was mentioned at the end of the XIXth - early XXth century by Mihai Ionescu – Dobrujanu and Grigore Tocilescu. Vasile Parvan has the idea of an archaeological research project in all of Dobruja, to which his students were to take part.

Archaeological investigations were initiated in 1924 by Grigore Florescu, Vasile Parvan`s assistant, who led the research at Capidava until 1960, the year of his death. Archeological excavations were interrupted until 1965, when they were taken over by Radu Florescu with the support of Dobruja`s Archaeological Museum (Today's National Museum of History and Archaeology of Constanta) and continued without interruption until present.

The archaeological site of Capidava had an important role in training future generations of archaeologists. It worked since 1967 as a school – site, initially receiving a smaller number of students, and then, starting 1988, there were created the conditions to sustain a meaningful participation in archaeological practice. Currently, at Capidava students from four universities in the country put their bases in archeology: Bucharest University, "Dimitrie Cantemir" Christian University of Bucharest, "Ovidius" University of Constanta and "Lucian Blaga" University of Sibiu.