Pre-Romanesque

In the 7th century, the Croats, with other Slavs and Avars, came from Northern Europe to the region where they live today. They were on the level of Iron Age nomadic culture, so they did not know how to enjoy the advantages of urban cities. This is why they first inhabited city boundaries on nearby rivers (like Jadro near Roman Salona).

The Croats were open to Roman art and culture, and first of all to Christianity. First churches were built as royal sanctuaries, and the influence of Roman art was strongest in Dalmatia where the urbanization was thickest and there were the largest number of monuments.^[4] Gradually that influence was neglected and certain simplification, alteration of inherited forms, and even creation of original buildings appeared. All of them (a dozen large ones and hundreds of small ones) were built with roughly cut stone (natively called – lomljenac) bounded with thick layer of mortar from outside. Large churches are longitudinal with one or three naves like the St. Saviour at the source of the river Cetina, built in the 9th century. The church has strong semi-circular buttresses that give a feeling of fortification, emphasized by the mighty bell-tower positioned in front of entrance.

Smaller churches often have several apses. The largest and most complicated central based church from the 9th century is the church of St. Donatus in Zadar. Around its circular centre – with dome above – is a nave in the shape of a ring with three apses directed to the east; that shape is followed on the second floor forming a gallery. For that period, with its size and beauty, St. Donatus is comparable only with the chapel of Charlemagne in Aachen.

The altar fences and windows of those churches were highly decorated with transparent shallow string-like ornament that is called pleter (meaning to weave) because the strings were threaded and rethreaded through itself. Motifs of those reliefs were taken from Roman art (waves, three-string interlace, pentagrams, net of rhomboids etc.), but while in Roman art they only made the frame of a sculpture, in the Dark Ages it fills the entire surface. Sometimes figures from Bible appeared alongside this decoration, like Relief in Holy Nedjeljica in Zadar, and then they were dominated by their pattern. This also happened to engravings in early Croatian script – Glagolitic. Soon, the Glagolitic writings were replaced with Latin on altar fences and architraves of old-Croatian churches. Those inscriptions usually mention to whom the church was dedicated, who built it and when it was built, as well who produced the building. That was the way that “barbarian newcomers” could fit amongst the Romanised natives.

By joining the Hungarian state in the twelfth century, Croatia lost its independence, but it did not lose its ties with the south and the west, and instead this ensured the beginning of a new era of Central European cultural influence.

Source: Wikipedia