During the stormy joint reigns of John and Cantacuzenus (1342 to 1355), the empire was attacked both by Tartars on the north, and by the Turks in Asia Minor. The Bulgarian and Serbian kingdoms had both gained strength during the Latin occupation at the expense of the empire, and were ready to avail themselves of the aid alike of Turks and Tartars in their endeavours to capture territory from the empire. When, in 1342, Cantacuzenus was attacked by the Bulgarians, a division of the Turks, whose emir had taken the title of sultan of Lydia, was induced to come to his aid. Twenty-nine thousand arrived at the mouth of the Maritza, the ancient Hebrus, and with their aid a temporary relief was afforded; but for some reason, possibly a severe winter, they withdrew to Asia Minor. The Bulgarians on this occasion were not aided by the Tartars, probably because the latter were occupied in the Crimea, and throughout what is now southern Russia, in fighting the Genoese, who had blockaded the northern coast of the Black Sea. Apocaukus, the rival of Cantacuzenus, succeeded in the following year in hiring a Turkish fleet and army. Both sides, indeed, in the civil war then going on, as well as the Bulgarians and Serbians, never hesitated to increase their armies by employing Turks or Tartars as auxiliaries. When, in 1344, Cantacuzenus promised his daughter Theodora in marriage to Orchan, he received at once the aid of a body of five thousand Ottoman Turks, and this number was increased when the marriage took place, two years later. But the young emperor John met him with another body of Turkish auxiliaries. Orchan would have made short work of John; for in an interview which took place with much ceremony and cordiality at Scutari to congratulate his father-in-law on his second coronation, he appears to have decided upon following the Turkish method of getting rid of a rival to the throne of his father-in-law. Cantacuzenus, however, would not sanction assassination. Orchan apparently could not understand any such scruples, and shortly afterwards sent a number of Turks to the capital on a pretended political mission, but really with the object of aiding Cantacuzenus by murdering John. The elder emperor, as soon as he learned the design, at once put his foot down, and declared that he would not permit John to go outside the palace except accompanied by him.[87]