Rightly known as the cradle of civilization, Mesopotamia, the fertile land between two rivers, gave us our oldest city, Jericho (ca. 8000 BCE), and our earliest writing system, cuneiform (ca. 3100 BCE). Other cities in the region include Uruk, Akkad, Assur, Babylon, Nimrud, Ninevah, and Persepolis; their still-impressive ruins and art speak of a world of luxury and high artistic achievement designed for a select fabulously wealthy few. Beyond the bustling urban centers, settlements built on mounds called tells contain the graves of local people, many buried with ceramics, bronze and iron weapons, and occasionally treasures of silver and gold. Camel caravans traveling along the Silk Road and from South Arabia brought cultures, goods, and would-be-conquerors into the region from west and east, most famously Alexander the Great (ca. 330 BCE). Greeks and Romans occupied and administered the region, but it retained its distinctive character. The rise of Islam (ca. 620 CE) and subsequent Islamic kingdoms such as the Umayyads, Abbasids, and Fatimids, led artists to create ornate, colorful glass, ceramic, and metal objects. The wealth of the Mamluk and early Ottoman (ca. 1300 CE) periods and cultural and military contacts with Europe created beautiful fusions in art and architecture, as in Moorish Spain.