Islamic art is vast both temporally and geographically, reaching from the seventh to the 16th century and from southern Spain all the way to Central Asia. Though Islamic art shows marked variety, its main concern lies in its association with the Qur'an. This attention to the holy book of the Islamic religion makes calligraphy a preeminent element of Islamic art. Complex geometric designs, a bold, graphic use of color, and nonrepresentational decoration in public art are emblematic as well. Figural elements have been largely excluded from Islamic religious art because the Qur'an clearly forbids the worship of idols, although figures do appear in decorative objects designed for private use and in courtly art. While painting and sculpture are dominant forms in the West, in the Islamic world illuminated manuscripts, woven textiles, mosaic and colored tile, and blown glass are primary forms. Art was commonly sponsored by the patronage of rulers, who were responsible for constructing and decorating the mosques, which served, not only as religious buildings, but as cultural and educational centers for Islamic culture. Islamic mosques and monumental structures display, in their intricacies of construction and decoration, a love of pure form, arabesque. Innovation in Islamic art began to wane in the 15th century, as many of the Islamic courts which had long funded the arts fell to imperialist influence. Though Islamic art stagnated for some time, it remains a rich element of religious worship and culture throughout the world, responsible for the preservation of techniques and artistic sensibilities that may otherwise have been lost.