The spatial design of the Church of the Holy Trinity at Sopo-cani conforms to the line of development of 13th-century Ser­bian churches built after Žica, which established the forms of the second, mature stage of the Raska style of architecture. It is an aisleless building with a semi-circular apse on its eas­tern end and a narthex, separated from the nave by a wall, on the western side. The nave consists of three bays, the cen­tral one surmounted by a dome. To the north and south of the space beneath the dome are choirs, open to it along their en­tire width. The prothesis and the diaconicon are formed in the continuation of the choirs, along the eastern bay. Two chapels were added to the sides of the narthex as separate premises.

As regards its spatial organization, the Church of the Holy Trinity does not offer any new elements. The arrangement established already at Žica was followed in all its main ele­ments. However, the differences in the upper structure show that between the construction of these two buildings impor­tant architectural developments had taken place which enrich­ed the fund of models and reflected the maturing of architec­tural expression on the territory of Serbia. The structure is simpler here. The narthex and the two end bays are covered with vaults which are slightly pointed at the top, of the kind, found in Raska from the beginning of the 13th century. The engaged lateral arches which support such vaults at 2ica and Mileseva are omitted here, as they had been in the earlier churches of the Holy Apostles, Morača and Pridvorica. The structure of the dome is also simplified. In the earliest Ras-ka-style churches, the dome rested on four internal engaged arches, which were built, like a canopy, against the lateral walls and on transverse arches, so that the weight was re­duced, by means of pendentives, to four points. All this was enclosed in the walls of the cubical base. In the churches built after 2ica — Mileseva, Holy Apostles and Pridvorica — there are double arches, but those on the inside are very narrow and do not spring from the base of the pillars, but rest on the imposts of the massive transverse arches. At Morača and Sopo­ćani they were omitted, the dome being supported by two trans­verse arches only. Double arches reappeared in later buildings, for they provided better static support. The builder of Sopocani was unable both to construct the dome in a professional way and to satisfy the demands of the founder as regards its form. Wishing to imitate the appearance of a Romanesque basilica and to emphasize the volume of the nave as much as possible, he placed the dome nearer the centre. In the earlier edifices of this type, the north and south walls of the circular dome base were raised on the longitudinal walls of the church, whereas at Sopocani, they are further in, resting on the engaged arches. Thus, another step in the external disposition of the mass was obtained to emphasize its height. In addition, the architect, probably fearing too much downward thrust, made these walls on the outside narrower than the arches which support them, while on the inside they project beyond the lower walls and rest on consoles, so that the span of the dome is diminished. The inexperience and lack of skill of the architect is apparent in the fact that he did not raise the cornice of the nave to a height sufficient to conceal completely the lateral engaged arches under the roof, but had to hew off some parts of them when making the roof so that they did not project from the surface of the facade. As a result, he created weak points in the building.

The lateral chapels are built next to the narthex, as at Žiča, but their form and structure are simpler. The apses are sunk into the wall and their entire area is covered with vaulting instead of cupolas. The ground plan of the altar area is the same as in the earlier churches — Žiča, Pridvorica and Morača.

While the overall design of the Sopocani church shows no major innovations, many of its external features are original. Under the influence of Romanesque architecture, the general appearance conceals the complexity of the ground plan. The nave is emphasized, covered with a pitched roof, and the cir­cular dome base is left unaccentuated. Here for the first time in Raska architecture, the lateral chapels are covered with sing­le low leanjto roofs. In that respect the Sopocani church is the closest of all the Serbian churches built up to that time to the Western basilica, for the transverse arms of the church — the low Raska transept — has completely disappeared here. These changes were adumbrated by some preceding edifices, but were indicated only in external features or in the relation-ship of the masses; nowhere had they been applied so consis­tently or on such a broad scale as at Sopocani.

The external appearance of the Sopocani church closely imi­tates Romanesque architecture. This became especially appa­rent later, when the spaces between the choirs and the lateral chapels were walled up. The Romanesque influence is reflect­ed both in the forms and in the decorative details. The build­ing has the appearance of a basilica, the nave being conside­rably higher than the two aisles and lit by clerestories. The impression of length is enhanced by the withdrawal of the dome from the plane of the longitudinal walls. Rows of small semi-circular blind arcades resting on consoles under the roof cornice decorate the western gable, the side walls of the nave, the dome and the eastern ends of the aisles. The arcading is interrupted by corner pilasters at the end of each row, and by pilaster strips in the centre of the long nave walls. The articula­tion of the facade by pilaster strips does not correspond to the interior lay-out or to the structural segments, and serves, as, in Romanesque churches, a purely decorative purpose. The drum of the dome is also divided by pilaster strips into eight sec­tions pierced by windows.

The white marble frames of the portals and windows are sim­ple in form and decoration, except for the recessed western portal, which is more elaborate. The recessions in the wall and the small octagonal columns flanking the doorway are continued in the horseshoe-shaped arches above the lunette. A series of cornices at the level of the lintel separates the lo­wer and the upper parts of the portal. A composition of The Descent of the Holy Ghost, the feast to which the church is dedicated, is painted in the lunette. The internal portal is without columns, but the archivolt formerly had relief deco­ration in stucco.

The side walls of the nave each have theree simple two-light windows. The windows in the altar apse, the west wall of the narthex and the west wall of the nave are similar, but slightly more ornate, having semi-circular archivolts. The west window of the nave, above the inner doorway, is the only one pre­served in ats entirety: the others lack mullions and capitals. The windows in the lateral chapels have one light and straight lintels. Only those in the choirs had a more elaborate frame.

All the windows were glazed with circular panes of stained glass: pink, yellow, blue and purple, as can be seen on the painted model of the church in the hands of King Uros in the founder's composition. Fragments of these were found during the archaeological excavations. The lower windows were pro­tected by iron bars.

The church was built of travertine ashlar and plastered on the outside with pale ochre mortar. The windows on the drum were framed with a painted decoration, of which only small parts of a dark-red band have been preserved. Thus the most prominent part of the church, which could be seen from a distance, had the most striking external features. Very little of the interior architectural decoration and the church furniture has been preserved. Some details can ne­vertheless be reconstructed on the basis of discoveries during the archaeological excavations. Their form, workmanship and material show that they were made with great care and pro­vided a warthy setting for the splendid paintings. The most prominent parts of the structure were emphasized with rich painted cornices of moulded decoration in good stucco tech­nique. The archivolt above the inner doorway was decorated in this may. It continued, on both sides, in a horizontal cornice which formed the upper edge of the first zone of paintings on the east wall of the narthex. Similar cornices decorated the beginning of the curve in the semi-calotte of the altar apse, the tops of the pilasters in the space under the dome, and, probably, the large icons on both sides of the alter screen. The screen itself, which separated the alter region from the nave, was carved of white marble and set between the two eastern pilasters. It consisted of a low parapet, made up of two slabs set in a moulded frame on each side of the main opening. Six small columns with capitals supproting the architrave rested on the parapet. Icons with rich stucco frames, probably made of mosaic and set on pilasters, formed a part of the altar screen, which was modelled on the screens of Byzantine churches, particularly those on the territory of Ser­bia. It was adapted to the lay-out of the eastern part of the church, but some details of its structure and finish were specific and bore traces of Romanesque influence. The marble screen which is now in the Sopocani church is a new and temporary one, but enough of the original screen has been found to enable us to reconstruct its basic form.