Though a great part of the royal letters from Tell el-Amarna is taken up with such rather wearisome requests for gold, they also give valuable glimpses into the political movements of the time. We gather, for instance, that Egypt succeeds in preventing Babylon from giving support to the revolts in Canaan, but she does not hesitate to encourage Assyria, which is now beginning to display her power as Babylon's rival. Burna-Buriash makes this clear when he complains that Akhenaten has received an embassy from the Assyrians, whom he boastfully refers to as his subjects; and he contrasts Babylon's own reception of Canaanite proposals of alliance against Egypt in the time of his father Kurigalzu. "In the time of Kurigalzu, my father," he writes, "the Canaanites sent to him with one accord, saying, 'Let us go down against the border of the land and invade it, and let us form an alliance with thee.' But my father replied to them, saying, 'Desist from seeking to form an alliance with me. If ye are hostile to the king of Egypt, my brother, and ally yourselves with one another, shall I not come and plunder you? For with me is he allied.' My father for thy father's sake did not hearken to them."[22] But Burna-Buriash does not trust entirely to the Egyptian's sense of gratitude for Babylon's support in the past. He reinforces his argument by a present of three manehs of lapis-lazuli, five yoke of horses and five wooden chariots. Lapis-lazuli and horses were the two most valuable exports from Babylon during the Kassite period, and they counterbalanced to some extent Egypt's almost inexhaustible supply of Nubian gold. Babylon at this time had no territorial ambitions outside the limit of her own frontiers. She was never menaced by Mitanni, and it was only after the fall of the latter kingdom that she began to be uneasy at the increase of Assyrian power.[23] Apart from the defence of her frontier, her chief preoccupation was to keep the trade-routes open, especially the Euphrates route to Syria and the north. Thus we find Burna-Buriash remonstrating with Egypt when the caravans of one of his messengers, named Salmu, had been plundered by two Canaanite chiefs, and demanding compensation.[24] On another occasion he writes that Babylonian merchants had been robbed and slain at Khinnatuni in Canaan,[25] and he again holds Akhenaten responsible. "Canaan is thy land," he says, "and its kings are thy servants;" and he demands that the losses should be made good and the murderers slain.[26] But Egypt was at this period so busy with her own affairs that she had not the time, nor even the power, to protect the commercial interests of her neighbours. For in the majority of the Tell el-Amarna letters we see her Asiatic empire falling to pieces.[27] From Northern Syria to Southern Palestine the Egyptian governors and vassal rulers vainly attempt to quell rebellion and to hold back invading tribes.