The second period of Siwa’s history is the most difficult to trace, especially with regard to the fixing of definite dates. One has to depend on the Arabic history at Siwa, and occasional highly coloured references to the oasis by the Arab historians and geographers. Siwa was known to the Arab writers as “Schantaria,” or “Santrieh,” spelt in various ways, which at a later date became “Siouah,” and finally “Siwa.” In 640 Egypt was invaded by a Mohammedan army commanded by Amrou, who seized the country from the feeble grasp of the representatives of Heraclius. The tide of conquest swept west along the northern coast of Africa. The disunion of the Berber tribes made the conquest of the country more easy for the host of Islam. Fugitives from the Arabs fled inland to the remote places such as the oases, and it was not until several centuries later that the Arabs established their religion in Siwa. According to the Arabic history when Egypt was invaded by the Mohammedans the Siwans sent an army to help repel the enemy, but this army, like many others, was lost in the desert. Mohammed Ben Ayas, an Arab historian who wrote in 1637, gives an account of the mysterious country of “Santarieh,” and describes how Moussa Ibn Nosseir was repulsed from its gates. In 708 Moussa attempted to reduce Siwa. He crossed the desert from Egypt in seven days. On arrival he found that all the Siwans had retired into their fortified town, which was surrounded by enormously high walls, with four iron gates. Finding it impossible to force an entrance he ordered his men to scale the walls and see what lay on the other side. With the aid of ladders they managed to reach the battlements, but each man who scaled the wall immediately disappeared over the other side and was never seen again. Moussa was so discouraged by this that he renounced his project and returned to Egypt, having lost a large number of soldiers. In 710 Tharic Ben Sayed, another Arab general, was also repulsed.