The documented presence of a bishop in Bari goes back to Gervasius, who attended the Council of Sardica in 347, and his successor Concordius, who was present at the Synod of Rome of 465, although names of their predecessors are preserved by tradition, beginning with Saint Maurus in the 1st century.
The bishop was elevated to an archbishop in the 6th century, and the presence of a cathedral in Bari is ascertainable from the same period.
Under the present nave are traces of an ancient church building with an apse, from the period before the first millennium, which had three aisles and square pilasters, and foundations on an axis slightly out of alignment with that of the present cathedral.
One of the mosaic pavements bears an inscription with the name of Bishop Andrea (758 - 761) and it seems highly likely that these are the remains of the first cathedral, which was destroyed in the 9th or 10th century.

In the first half of the 11th century the then archbishop (1025–1035) ordered the construction of a new episcopal church, which was finished under his successors Nicola I (1035–1061) and Andrea II (1061–1068).
This church was then destroyed by William the Wicked (William I of Sicily) along with the rest of the city (only the Basilica of St. Nicholas was spared), which took place in 1156.
At the end of the 12th century Archbishop Rainaldo began the reconstruction of the cathedral, reusing materials from the preceding church and other destroyed buildings.
Consecrated on 4 October 1292, the new cathedral was built in the style of the Basilica of St. Nicholas, which had served as the episcopal seat in the interim.

During the 18th century the façade, the nave and aisles, the Trulla (the ancient baptistry of the 12th century, today the sacristy) and the crypt were refurbished in Baroque style under Archbishop Muzio Gaeta according to designs by Domenico Antonio Vaccaro.
The building later underwent a series of refurbishments, demolitions and extensions.
The original Romanesque appearance of the interior was restored in the 1950s.
The last two restorations were those of, firstly, the late 20th century, which has restored the clarity of the Romanesque structures, and secondly, the 21st century, which has refurbished the interior.
The documented presence of a bishop in Bari goes back to Gervasius, who attended the Council of Sardica in 347, and his successor Concordius, who was present at the Synod of Rome of 465, although names of their predecessors are preserved by tradition, beginning with Saint Maurus in the 1st century. The bishop was elevated to an archbishop in the 6th century, and the presence of a cathedral in Bari is ascertainable from the same period. Under the present nave are traces of an ancient church building with an apse, from the period before the first millennium, which had three aisles and square pilasters, and foundations on an axis slightly out of alignment with that of the present cathedral. One of the mosaic pavements bears an inscription with the name of Bishop Andrea (758 - 761) and it seems highly likely that these are the remains of the first cathedral, which was destroyed in the 9th or 10th century.
In the first half of the 11th century the then archbishop (1025–1035) ordered the construction of a new episcopal church, which was finished under his successors Nicola I (1035–1061) and Andrea II (1061–1068). This church was then destroyed by William the Wicked (William I of Sicily) along with the rest of the city (only the Basilica of St. Nicholas was spared), which took place in 1156. At the end of the 12th century Archbishop Rainaldo began the reconstruction of the cathedral, reusing materials from the preceding church and other destroyed buildings. Consecrated on 4 October 1292, the new cathedral was built in the style of the Basilica of St. Nicholas, which had served as the episcopal seat in the interim.
During the 18th century the façade, the nave and aisles, the Trulla (the ancient baptistry of the 12th century, today the sacristy) and the crypt were refurbished in Baroque style under Archbishop Muzio Gaeta according to designs by Domenico Antonio Vaccaro. The building later underwent a series of refurbishments, demolitions and extensions. The original Romanesque appearance of the interior was restored in the 1950s. The last two restorations were those of, firstly, the late 20th century, which has restored the clarity of the Romanesque structures, and secondly, the 21st century, which has refurbished the interior.
Bari Cathedral