The Basilica of St. Nicholas was built in the late 11th century to shelter and venerate the relics of St. Nicholas that reached Bari on May 9th, 1087 from the homonymous church in Myra, Lycia (modern-day Turkey). The classical Romanesque-style basilica is located within the ancient fortified citadel, once occupied by the Catapan Court. It is the main structure within the St. Nicholas Citadel which also encompasses a series of other buildings constructed over time:
- Church of San Gregorio, the oldest consecrated church in the city;
- Convent;
- Basilica library and archives that conserve paper and parchment documents of exceptional historical value;
- St. Nicholas Study Centre;
- Portico dei Pellegrini, or Pilgrims’ Portico (completely missing today because lost in 1950s restoration works) once located in the area where the Middle School “San Nicola” currently stands;
- St. Nicholas Museum, inaugurated on February 6th, 2010, that displays some of the most precious pieces from the Basilica Archive and Treasury.
For hundreds of years, solid fortified walls surrounded the St. Nicholas Citadel to safeguard the area. Three access gates interrupted the walls through Via Palazzo, the Angevin arch, and Via Vanese. The Basilica itself is surrounded by three squares that were interconnected during the restoration works carried out in the last century. These works significantly modified the layout of the premises. Prior to the construction of the seaside promenade in the 1930s, the sea lapped the east side of the complex. The main access to the front square was, therefore, through the ancient "Via Francigena", which today corresponds to the street called Strada Palazzo di Città. This road was once an ancient pilgrims’ route that guided pilgrims to the basilica in order to honour St. Nicholas, thus, becoming a meeting point between East and West.
Abbot Elias ordered the construction of the crypt that was destined to shelter the remains of the saint. Work began in 1087 and ended in 1089 with its consecration by Pope Urban II. The construction of the basilica, on the other hand, commenced with Elias’s successor, the abbot Eustace. It was consecrated on June 22nd, 1197.
Prior to the late 19th century, the edifice had undergone periodic modifications that had altered its original appearance, but not its integrity. At the beginning of the 20th century, however, the Ministry of Justice and of Religious Affairs inaugurated the "Grand Restorations" season (1925-1934) that restored the basilica to its current appearance.
The basilica is built of limestone, some of which had been re-purposed from other buildings. Two low massive towers frame the main façade: Torre del Catapano (The Catapan’s Tower) on the right, and Torre della Milizia (The Militia Tower) on the left; the latter is lower and shows different craftsmanship. The outer facade displays projecting pilasters and three access portals, and reflects the internal tripartite nave division. The central portal is the largest of the three and is richly carved with strong symbolic elements. It re-evokes the image of Christ’s victory over the gloom of paganism as can be seen through the archivolt decorations, the sculpture depicting a sphinx on the cusp of the protruding porch, and the oxen supporting the octagonal columns standing on either side of the portal.
The monofora and bifora windows (single and double light mullioned windows) positioned on multiple orders and the central oculus on the façade, as well as the deep blind six-arch loggias along the different-length sides of the building attenuate the austere Romanesque appearance. The beautiful portal of the Lions is found on the north side of the building.
The church interior has a Latin Tau-cross plan (i.e., T-shaped with the transept placed at the end of the nave), and is divided longitudinally into three naves by columns and pillars. A beautiful wooden ceiling covers the central nave, and frames richly ornate paintings by Carlo Rosa from Bitonto. The high altar is located at the end of the central nave, and is surmounted by the oldest ciborium in Apulia (12th century). The apse houses "Elias’s Cathedra", a marble bishop’s throne (late 11th - early 12th century). The mosaic-like decoration around the throne displays an Arabic Kufic script bearing the word "Allah", interpreted by some as evidence of the multi-ethnic craftsmanship employed in constructing the throne.
The late 16th-century tomb of Bona Sforza, Duchess of Bari and Queen of Poland, is positioned behind the bishop’s throne. The Queen’s remains were initially placed in the cathedral, but later entombed in the basilica. The tomb stands between two semi-nude female figures, representing Bari and Poland, and two images of the saints Nicholas and Stanislaus.
Other noteworthy works of art are:
- in the left apse: the altarpiece dating to the second half of the 15th century, attributed to Vivarini (Venetian painter working in Apulia), which portrays a sacred conversation between St. James and St. Ludwig, on the one hand, and St. Nicholas and St. Peter on the other; the Enthroned Virgin Mary with Child stands in the centre.
- in the right transept: the “Silver Altar” (1319-1684), donated in 1319 by the tsar of Serbia Uroš II Milutin to cover the Saint's tomb in the crypt. In 1684, the Basilica commissioned two Neapolitan artists, Domenico Marinelli and Ennio Avitabile, the rebuilding of the altar in the dominant Baroque style of the period.
- on the right apse altar: the triptych (1451) by the 15th-century painter Andrea Rico from Heraklion, very active in many Italian cities. Our Lady of the Passion is here depicted between St. Nicholas, on the right, and St. John the Evangelist, on the left. It was customary to depict the Mother Mary in consideration of the local devotional context of the city where Her image was portrayed (e.g. Bergamo, Florence, Parma, etc.)

Two wide staircases in the lateral aisles lead down to the crypt that shelters the saint’s relics. The presence of an Orthodox chapel in the crypt is noteworthy as it denotes the coexistence of two religions. Indeed, the crypt houses two altars; one dedicated to the Catholic rite, and the other to the Orthodox rite. This is a unique reality in the Catholic world that warrants the ecumenical vocation in the Bari territory. The basilica has continued to be an important pilgrimage destination throughout the centuries. Devotees come from all over the world, especially from the particularly devout Orthodox Russia, to venerate St. Nicholas. The crypt features a series of capitals, no two alike; some are called "double-faced". The "miraculous" porphyry column stands in the south corner.