<P> According to the Periplus, numerous Greek seamen managed an intense trade with Muziris: </P> <P> Then come Naura and Tyndis, the first markets of Damirica (Limyrike), and then Muziris and Nelcynda, which are now of leading importance . Tyndis is of the Kingdom of Cerobothra; it is a village in plain sight by the sea . Muziris, of the same Kingdom, abounds in ships sent there with cargoes from Arabia, and by the Greeks; it is located on a river, distant from Tyndis by river and sea five hundred stadia, and up the river from the shore twenty stadia" </P> <P> The Periplus Maris Erythraei mentions a marketplace named Poduke (ch. 60), which G.W.B. Huntingford identified as possibly being Arikamedu in Tamil Nadu, a centre of early Chola trade (now part of Ariyankuppam), about 3 kilometres (1.9 mi) from the modern Pondicherry . Huntingford further notes that Roman pottery was found at Arikamedu in 1937, and archeological excavations between 1944 and 1949 showed that it was "a trading station to which goods of Roman manufacture were imported during the first half of the 1st century AD". </P> <P> Following the Roman - Persian Wars, the areas under the Roman Byzantine Empire were captured by Khosrow II of the Persian Sassanian Dynasty, but the Byzantine emperor Heraclius reconquered them (628). The Arabs, led by' Amr ibn al -' As, crossed into Egypt in late 639 or early 640 CE . This advance marked the beginning of the Islamic conquest of Egypt and the fall of ports such as Alexandria, used to secure trade with the subcontinent by the Roman world since the Ptolemaic dynasty . </P>

When did indian ocean trade become most active