The Komnenoi were great patrons of the arts, and with their support Byzantine artists continued to move in the direction of greater humanism and emotion, of which the Theotokos of Vladimir, the cycle of mosaics at Daphni, and the murals at Nerezi yield important examples. Ivory sculpture and other expensive mediums of art gradually gave way to frescoes and icons, which for the first time gained widespread popularity across the Empire. Apart from painted icons, there were other varieties - notably the mosaic and ceramic ones. Some of the finest Byzantine work of this period may be found outside the Empire: in the mosaics of Gelati, Kiev, Torcello, Venice, Monreale, Cefalù and Palermo. For instance, Venice's Basilica of St Mark, begun in 1063, was based on the great Church of the Holy Apostles in Constantinople, now destroyed, and is thus an echo of the age of Justinian. The acquisitive habits of the Venetians mean that the basilica is also a great museum of Byzantine artworks of all kinds (e.g., Pala d'Oro). Centuries of continuous Roman political tradition and Hellenistic civilization underwent a crisis in 1204 with the sacking of Constantinople by the Venetian and French knights of the Fourth Crusade, a disaster from which the Empire recovered in 1261 albeit in a severely weakened state. The destruction by sack or subsequent neglect of the city's secular architecture in particular has left us with an imperfect understanding of Byzantine art. Although the Byzantines regained the city in 1261, the Empire was thereafter a small and weak state confined to the Greek peninsula and the islands of the Aegean. During their half-century of exile, however, the last great flowing of Anatolian Hellenism began. As Nicaea emerged as the center of opposition under the Laskaris emperors, it spawned a renaissance, attracting scholars, poets, and artists from across the Byzantine world. A glittering court emerged as the dispossessed intelligentsia found in the Hellenic side of their traditions a pride and identity unsullied by association with the hated "latin" enemy. With the recapture of the capital under the new Palaeologan Dynasty, Byzantine artists developed a new interest in landscapes and pastoral scenes, and the traditional mosaic-work (of which the Chora Church in Constantinople is the finest extant example) gradually gave way to detailed cycles of narrative frescoes (as evidenced in a large group of Mystras churches).