This map of the Indian Ocean and the China Sea was engraved in 1728 by the Hungarian-born Ottoman cartographer and publisher Ibrahim Müteferrika; it is one of a series that illustrated Kâtib Çelebi’s Cihannuma (Universal Geography), the first printed book of maps and drawings to appear in the Islamic world. CAMBRIDGE UNIVERSITY LIBRARY
Besides sailing across the Indian Ocean, there was another sea route from Arabia to India, the oldest of them all. It was not dependent on the monsoon and could be sailed without knowledge of the stars. The Arabian Gulf was the natural corridor between Mesopotamia and India, and the voyage could be made in small boats simply by hugging the coast, always keeping land in sight. Maritime contacts between Mesopotamia and India through Gulf waters go back to the very beginnings of urban civilization in the third millennium BC, when Sumer on the Tigris and Euphrates Rivers was in touch with Harappa on the Indus.

Unlike the Red Sea, whose reef-filled waters and complex wind regime required skilled pilotage, the Arabian Gulf was relatively easy to navigate. While the shores of the Red Sea were sparsely inhabited and almost waterless, the headwaters and eastern shore of the Gulf were home to ancient civilizations. Along its coasts have been found the scattered evidence of some five millennia of trade: fragments of pre-Sumerian al-‘Ubaid pottery from the third millennium BC, Chinese celadon and early Islamic glazed jars, Indian bangles, Gujarati carnelian beads, 19th-century coffee cups, Roman coins and the occasional Chinese cash.

Mughal Library