The so-called Great Basilica was the principal church in late antique Butrint and sections of a 6th century mosaic floor are still preserved. The church was erected on the site of a cistern belonging to the Roman city’s aqueduct and is over 30m long. It followed the characteristic plan and architectural devices prevalent throughout Epirus, employing a central nave flanked by aisles that were screened from the nave by closed colonnades.
At the east end was a tripartite transept and a central pentagonal apse. Remains of the mosaic pavement include trailing ivy tendrils and scrolling guilloche that are also found in the Baptistery, indicating that these two religious monuments are broadly contemporary. The devices are characteristic of mosaicists working in Nikopolis in northwestern Greece. Some time later, most likely in the 13th century when Butrint began to boom once more, the Great Basilica was extensively rebuilt and effectively became Butrint’s cathedral.
References:Visby Cathedral (also known as St. Mary’s Church) is the only survived medieval church in Visby. It was originally built for German merchants and inaugurated in 1225. Around the year 1350 the church was enlarged and converted into a basilica. The two-storey magazine was also added then above the nave as a warehouse for merchants.
Following the Reformation, the church was transformed into a parish church for the town of Visby. All other churches were abandoned. Shortly after the Reformation, in 1572, Gotland was made into its own Diocese, and the church designated its cathedral.
There is not much left of the original interior. The font is made of local red marble in the 13th century. The pulpit was made in Lübeck in 1684. There are 400 graves under the church floor.