After Thothmes III had secured the predominance of Egypt in Syria and Palestine he recognized Assyria as an independent power, and supplied its king with Egyptian gold to assist him, no doubt, in strengthening his territory against their common enemy. Gifts were also sent from Assyria to Egypt to fan the flame of cordial relations. The situation was full of peril for Saushatar, king of Mitanni. Deprived by Egypt of tribute-paying cities in Syria, his exchequer must have been sadly depleted. A standing army had to be maintained, for although Egypt made no attempt to encroach further on his territory, the Hittites were ever hovering on his north-western frontier, ready when opportunity offered to win back Cappadocia. Eastward, Assyria was threatening to become a dangerous rival. He had himself to pay tribute to Egypt, and Egypt was subsidizing his enemy. It was imperative on his part, therefore, to take action without delay. The power of Assyria had to be crippled; its revenues were required for the Mitannian exchequer. So Saushatar raided Assyria during the closing years of the reign of Thothmes III, or soon after his successor, Amenhotep II, ascended the Egyptian throne. Nothing is known from contemporary records regarding this campaign; but it can be gathered from the references of a later period that the city of Asshur was captured and plundered; its king, Ashur-nadin-akhe, ceased corresponding and exchanging gifts with Egypt. That Nineveh also fell is made clear by the fact that a descendant of Saushatar (Tushratta) was able to send to a descendant of Thothmes III at Thebes (Amenhotep III) the image of Ishtar (Shaushka) of Nineveh. Apparently five successive Mitannian kings were overlords of Assyria during a period which cannot be estimated at much less than a hundred years. Our knowledge regarding these events is derived chiefly from the Tell-el-Amarna letters, and the tablets found by Professor Hugo Winckler at Boghaz-Köi in Cappadocia, Asia Minor. The Tell-el-Amarna letters were discovered among the ruins of the palace of the famous Egyptian Pharaoh, Akhenaton, of the Eighteenth Dynasty, who died about 1358 B.C. During the winter of 1887-8 an Egyptian woman was excavating soil for her garden, when she happened upon the cellar of Akhenaton's foreign office in which the official correspondence had been stored. The "letters" were baked clay tablets inscribed with cuneiform alphabetical signs in the Babylonian-Assyrian language, which, like French in modern times, was the language of international diplomacy for many centuries in Western Asia after the Hyksos period.