Before the end of the year 1372, it was recognized that the Osmanlis had come into the Balkans to stay. The conquest of Macedonia east of the Vardar, following so closely upon the subjugation of southern Bulgaria and the completion of the Thracian conquest, gave to Murad a preponderant position in the Balkan peninsula. The Byzantine emperor and the Bulgarian and Serbian princes were his tributaries. Wallachia, Bosnia, Albania, Epirus, Thessaly, Attica and the Peloponnesus were now on the confines of the Ottoman Empire, and menaced by Ottoman invasion.
In Europe, Murad was credited with having the intention of invading Hungary. It was reported that he had made an alliance with the Tartars of Russia to attack Hungary. The Tartars were to cross the Carpathians by way of Moldavia into Transylvania, while Murad was to work his way up the valley of the Danube.[344] Murad may have dreamed of such a project, just as he had thought of making a supreme effort to enter Constantinople after his first Thracian campaign. But, if he did, he was deterred by the same well-grounded fear of moving too fast. Ten years before he had refrained from committing a fatal error. He would continue to make haste slowly. The early Osmanlis were not raiders. They were empire-builders. They succeeded because they never forgot that their greatest problem was that of assimilation. When they extended their conquests beyond the area of possible assimilation, the period of decay automatically commenced.
The decade following the Macedonian campaign of 1371-2 was spent in ottomanizing southern Bulgaria and eastern Macedonia, in completing the assimilation of Thrace, in reorganizing the army, and in a rearrangement of the system of distributing the timarets or military fiefs. Royal domains were created, and lands were set aside for the support of the mosques and other religious institutions in the form of inalienable endowments (vakufs).
The only move of Murad against the Hungarians was to send five thousand archers, upon the request of the Senate, to help the Venetians in their war against Louis.[345]
After the Macedonian campaign, Murad turned his attention once more to Byzantium. John, when he returned from his unsuccessful trip to Rome, placated Murad by sending his third son, Theodore, to serve in the Ottoman army. In 1373, John, passing over Andronicus, raised Manuel to the imperial purple as co-emperor. The disloyalty of his eldest son in the question of the emperor’s ransom from his Venetian creditors made it natural that John should have selected Manuel to rule with him.
John was not wrong in his estimate of the character of Andronicus. The disappointed prince entered into a conspiracy with Saoudji, son of Murad, who had been entrusted with the command of the Thracian army while his father was occupied in Anatolia. John and Manuel, according to some accounts, were also in the field with Murad. So the moment was propitious. The two sons raised the standard of revolt against their fathers.[346] Murad, who hated his own son and feared him, crossed immediately into Thrace. The army which was supporting the cause of the young princes abandoned them, and the rebels fled to shut themselves up in Demotika.[347]
Faced with starvation, the inhabitants of Demotika opened the gates of their city to Murad. He exacted a most atrocious vengeance. The garrison were bound hand and foot and thrown into the river. The young Osmanlis and Greeks who had been led astray by the princes, were put to death. Wherever possible Murad compelled fathers to act as executioners of their sons. He set the example by tearing out Saoudji’s eyes, and then cutting off his head.[348]
It has been generally written that Murad intended that the same punishment should be meted out to Andronicus. For the sake of appearances, he did order John Palaeologos to have his son’s eyes put out. But there was no order for execution. John Palaeologos consented to the blinding of Andronicus and of his grandson and namesake, who was only five years old.[349] The operation was not successfully performed. Both Andronicus and his son, even if temporarily blinded, recovered their eyesight. Some have explained this by stating that they were healed by a Genoese physician.[350] There is recorded a beautiful story that Andronicus owed the restoration of his sight to the empress, his mother, who visited him daily in the tower of Anemas and was prodigal in her efforts to heal him. He was in despair for some months, until one day he saw a lizard climbing on a wall.[351]
If Murad had really desired the death or total blindness of Andronicus, he could easily have secured this result. While punishing his own son, however, he saw to it that Andronicus escaped the consequences of the same crime. Here we have a revelation of the far-sightedness and cold-bloodedness of Murad. He killed his own son, because he feared his rivalry. He spared the son of John Palaeologos in order to perpetuate the rivalry between the emperor and his son. To have killed or incapacitated Andronicus would have been from his view-point an act of folly rather than of justice; for Andronicus, brilliant, adventurous, magnetic, was at the same time a worthy exemplar of the name he bore, a name that stood for the acme of unscrupulous conduct and contempt for ties of blood. Murad had only to wait, and history would repeat itself. Internal dissensions in the family of the Palaeologi had made the fortunes of Orkhan. Murad had no intention of getting rid of Andronicus, in whom he saw the means of still further enmeshing the Byzantine emperors.[352]
The Byzantine historians record for the year 1374 another event, which illustrates the power of Murad over John Palaeologos. Manuel, who had resumed the government of Salonika, tried to induce the inhabitants of Serres to recover their liberty by massacring the Ottoman garrison and the Ottoman colonists. Serres, in spite of its prominent place in recent Serbian history, was regarded by the Byzantines (as it still is by the Greeks of to-day) as a city of their compatriots. We have no means of establishing the grounds upon which Manuel believed it possible to restore the Byzantine authority in the country between the Struma and the Vardar. The sequel indicates that it was a wild and unfounded hope of a desperate man, and shows how thoroughly in two years the Osmanlis had become masters of the situation in Macedonia.