The Citadel, situated in the very geographical centre of the island, has been aptly called the Crown of Gozo. It is possible that it was the centre of activity since prehistoric times, that is around 7000 years ago when the Maltese archipelago was inhabited for the first time by people that crossed over from Sicily. Later on there was also activity as from the present day Rabat. Its antiquity was startingly revealed in a sewer trench cut along the south side of ‘It-Tokk’, the main square of the city, in 1960. Natural blue clay was covered by a 3.70 metre depth of artificial accumulation below the modern pavement. The lowest level was laid down in the Bronze Age, with sherds of the Borg-in Nadur phase (1500 – 700BC)

In 700BC, the island was colonized by the Phoenicians and Carthaginians. The Punic level within the trench at It-Tokk was, alas, fairly thin and, in the restricted area available for examination, there was no sign of structures. There is however no doubt that the town was inhabited in Punic times. Punic remains have been unearthed to the south west, from the area running roughly from Triq Vajringa to Pjazza San Frangisk.

The Romans took over in 218BC at the beginning of the second Punic War and created Gozo a municipium independent of Malta with a republican sort of Government that minted its own coins. During the Roman period, several buildings stood at It-Tokk. At one point the above mentioned trench, a cellar still containing wine jars was found, though the jars were empty. It is in fact pretty certain that a Roman town developed in Rabat known as Gaulos Oppidum – the town of Gozo. Its limits are partly marked by the discovery from time to time of huge blocks of stone – part of the foundations of the Roman houses – and of tombs, which were placed immediately outside the town. Its bownfary was probably in what is nowadays Triq Palma, hence made a ninety degrees turn onto the right into Triq Vajringa, and another ninety degrees to the right down Triq Santa Marija, il-Mandragg.

The Citadel and Rabat continued to be inhabited under the Byzantines (535 – 870) who seemingly did not carry out any work significance. At one point in the trench of It-Tokk, in a building that had been burnt down, there were some fifth century oil lamps on the floor. It was late during the Arab period (870 – 1127) that the town of Gozo got its name of Rabat.

The Arab rule was brought to an end in 1091 by the Normans, who were in turn followed by the Swabians (1194), the Angevines (1266), and the Aragonese (1282). The population of Gozo concentrated in the castrum began rising steadily. The castrum is mentioned in a report of 1241 when it was the only fortified shelter on the island. Another proof of the rising population is the Rabat cemetery in an area aptly known as Fuq it-Tomba next to Pjazza Sant Wistin. Some remains possibly date to around 1270, when the island was under the Angevines. By 1435, the Citadel had a Matrice: the Sanctae Mariae Ecclesiae dedicated to the Assumption of the Virgin Mary into Heaven. On the other hand in Rabat three parishes are recorded namely the parish of Saint George, of Santa Marija ta’ Savina and of Saint James.

The arrival of the Knights of Saint John in 1530 brought little changes to the Citadel and Rabat. In July 1551, Gozo suffered its worst siege in history. Almost the whole population was dragged into slavery. By September 1554, the Matrice was functioning again and Rabat was partly abandoned and inhabited again some years later.

In 1599 works were started to rebuild the Castello under the direction of Giovanni Rinaldini. By 1603 the Maltese military engineer Vittorio Cassar was entrusted to supervise the works at a time they had already reached an advanced stage.

Access to the Citadel was up a street ramp from It-Tokk, upon a stone bridge across the ditch, and another ramp to the Citadel entrance, that could be sealed by a draw bridge.

Until 15 April 1637, Gozitans were bound by law to spend the night within the Citadel. After 1637, there was an exodusium to Rabat that continued to grow steadily throughout the years.

After a short-lived French rule (June-October 1798) and twenty one months of autonomous rule (1798 – 1800), in 1800 Malta and Gozo passed under British rule. On 16 September 1864, Gozo became a diocese separate from Malta. This event became possible through the efforts of two Gozitans: Don Pietro Pace and Sir Adrian Dingli, then the Crown Counsel. Malta and Gozo became indipendent on 21 September 1964 and were declared Republic on 13 December 1974.