The discussion emphasizes the peculiarity and individuality of both the shape and style of Dalmatian hexaconchs. Together with the rotunda of Holy Trinity at Zadar, they surely represent the most original architectural creation of early medieval Dalmatia and its specific cultural milieu which grew from a twofold tradition in a true symbiosis of the European East and West in the Adriatic area. Their mutual interdependence in Dalmatia was articulated through the individual shapes of religious architecture. These hexaconchs are a form specific to only the innermost part of Dalmatia, centred on the area between Zadar and Split, and deep into the hinterland of these towns, which corresponded to the Croatian principality.Certainly, buildings as special as this had their own original matrix - an individual spatial composition and a specific structure which formed their body. Without this, the hexaconchs would not have possessed the originality which has been observed by all the scholars who have written about them. Indeed, they have their own shape and style. By analyzing and interpreting the legacy of Dalmatian religious architecture, it seems plausible to assume that the early Christian baptistery of Zadar Cathedral may have served as a model not only for their hexaconchal shape and spatial structure but also for their dimensions and proportions. In the regional architecture prior to the period when the hexaconchs were built, no other building, aside from the Zadar baptistery, had such a shape and such a compositional compatibility with the hexaconchs; the very structure and measurements of their interior space. However, the architectural style of the hexaconchs, which display pilaster strips on their exteriors, and their vocabulary of pre-Romanesque language find their parallels on the monumental rotunda of Holy Trinity - a chapel adjacent to the baptistery itself, located nearby in the same episcopal complex - more than on any other late Antique or early medieval building both in the immediate region and in the whole Adriatic basin. For this reason, the search for the origin of the shape and style of Dalmatian hexaconchs leads us to Zadar and it is no wonder that almost every scholar who has studied this group of buildings has pointed to this fact. Their geographical distribution also witnesses this influence in its own way: two hexaconchs can be found at Zadar, while four or even five more are located in the wider Zadar area, adding up to seven out of the ten Dalmatian hexaconchs in total.This number implies that this group of rotundas, being characteristic for a specific period in Dalmatia, was created in a relatively short period of time. Moreover, it points to the building and carving workshops which, drawing upon the same source model, constructed the hexaconchs and provided them with stone liturgical furnnishings. In particular, further indications can be found in the production of the socalled Benedictine carving workshop, probably located at Zadar, a workshop from the time of Prince Trpimir which produced the furnishings for the hexaconchs at Pridraga and Kašić, and the carving workshop from Trogir which was responsible for the carvings at Trogir and Brnaze. All of these, with regard to the hexaconchs, testify to predominantly early ninth-century production, and represent the main argument for the dating of these interesting Dalmatian rotundas to the same time. Apart from their original pre-Romanesque shape, the majority of the free-standing hexaconchal rotundas were provided with early Romanesque additions during the course of time, and these additions turned these hexaconchs into small complexes of sorts. Vestibules created in this period suggest two possiblities: according to one, the vestibules added in this manner were actually a kind of exterior crypt, spaces where sarcophagi could be housed, and according to the other, some of these vestibules were also provided with bell-towers built on top of them. The latter possibility is implied by the dispositions of the suggested bell-towers and the strength of the supporting substructions (e.g. the Stomorica church at Zadar or the hexaconch at Kašić), but also by the stylistic elements which point to the early Romanesque, and architectural details, the function of which indicates a bell-tower (e.g. impost capitals of the Stomorica church or St Chrysogonus at Zadar, and an octogonal colonette from Kašić).
K2-19, The first K2 muti-planetary system showing TTVs
