become depopulated due to Turkish raiding in the late eleventh century. Yet as the Komnenian emperors built up extensive fortifications in rural areas during the twelfth century, repopulation of the countryside took place. Overall, given that both population and prosperity increased substantially in this period, economic recovery in Byzantium appears to have been strengthening the economic basis of the state. This helps to explain how the Komnenian emperors, Manuel Komnenos in particular, were able to project their power and influence so widely at this time. The new wealth being generated during this period had a positive impact on Byzantine cultural life. In artistic terms, the twelfth century was a very productive period in Byzantine history. There was a revival in the mosaic art, and regional schools of Architecture began producing many distinctive styles that drew on a range of cultural influences. According to N. H. Baynes in Byzantium, An Introduction to East Roman Civilization, Andronikos I Komnenos and the fall of the Komnenoi Manuel's death on 24 September 1180, marked a turning point in the fortunes of the Byzantine Empire. When Manuel died, he was succeeded by his young son Alexios II Komnenos, who was under the guardianship of the empress Maria. Her conduct excited popular indignation, and the consequent disorders, amounting almost to civil war, gave an opportunity to the ambition of Manuel's estranged cousin, Andronikos I Komnenos (r. 1183–1185), son of Isaac Komnenos. Andronikos left his retirement in 1182, and marched on Constantinople with an army that (according to non-Byzantine sources) included Muslim contingents. His arrival was soon followed by a massacre of the Latin inhabitants, which was focused on the Venetian merchants who were settled in some numbers in Constantinople. He was believed to have arranged the poisoning of Alexios II's elder sister Maria the Porphyrogenita and her husband Renier of Montferrat, although Maria herself had encouraged him to intervene. The poisoner was said to be the eunuch Pterygeonites. Soon afterwards he had the empress Maria imprisoned and then killed, by Pterygeonites and the hetaireiarches Constantine Tripsychos. Alexios II was compelled to acknowledge Andronikos as colleague in the empire, but was then put to death; the killing was carried out by Tripsychos, Theodore Dadibrenos and Stephen Hagiochristophorites. Andronikos, by 1183 sole emperor, married Agnes of France, a child twelve years of age who had been formerly betrothed to Alexios II. Agnes was a daughter of King Louis