diplomatic relations and friendly or offensive alliances. The palace of Trebizond was famed for its magnificence, the court for its luxury and elaborate ceremonial, while at the same time it was frequently a hotbed of intrigue and immorality. The Grand Comneni were also patrons of art and learning, and in consequence of this Trebizond was resorted to by many eminent men, by whose agency the library of the palace was provided with valuable manuscripts and the city was adorned with splendid buildings. The writers of the time speak with enthusiasm of its lofty towers, of the churches and monasteries in the suburbs, and especially of the gardens, orchards and olive groves. It excited the admiration of Gonzales Clavijo, the Spanish envoy, when he passed through it on his way to visit the court of Timur at Samarkand (Clavijo, Historia del gran Tamorlan, p. 84), and Cardinal Bessarion, who was a native of the place, in the latter part of his life, when the city had passed into the hands of the Mahommedans, and he was himself a dignitary of the Roman Church, so little forgot the impression it had made upon him that he wrote a work entitled "The Praise of Trebizond" (Έγκώμιον ραπεζοῠντος), which exists in manuscript at Venice. Little was known of the history of the empire of Trebizond until the subject was taken in hand by Professor Fallmerayer of Munich, who discovered the chronicle of Michael Panaretus among the books of Cardinal Bessarion, and from that work, and other sources of information which were chiefly unknown up to that time, compiled his Geschichte des Kaiserthums von Trapezunt (Munich, 1827). From time to time the emperors of Trebizond paid tribute to the Seljuk sultans of Iconium, to the grand khans of the Mongols, to Timur the Tatar, to the Turkoman chieftains, and to the Ottomans; but by means of skilful negotiations they were enabled practically to secure their independence. We find them also at war with many of these powers, and with the Genoese, who endeavoured to monopolize the commerce of the Black Sea. The city was several times besieged, the most formidable attack being that which occurred in the reign of Andronicus I., the second emperor, when the Seljuks, under the command of Melik, the son of the great sultan Ala-ed-din, first assaulted the northern wall in the direction of the sea, and afterwards endeavoured to storm the upper citadel by night. They failed, however, in both attempts; and in the latter, owing to the darkness, and to the occurrence of a violent storm which suddenly swelled the torrents in the ravines, their force was thrown into inextricable confusion, and they were compelled to abandon their camp and make the best of their escape from the country. So great was the strength of the fortifications that Mahommed II. might have experienced much difficulty in reducing it, had it not been for the pusillanimous conduct of David, the last emperor, who surrendered the place almost unconditionally.
Ancient Memorials.—Several interesting monuments of this period remain at Trebizond in the form of churches in the Byzantine style of architecture. One of these is within the area of the old city, viz. the church of the Panaghia Chrysokephalos, or Virgin of the Golden Head, a large and massive but excessively plain building, which is now the Orta-hissar mosque. On the farther side of the eastern ravine stands a smaller but very well proportioned structure, the church of St Eugenius, the patron saint of Trebizond, now the Yeni Djuma djami, or New Friday mosque. Still more important is the church of Haghia Sophia, which occupies a conspicuous position overlooking the sea, about 2 m. west of the city. The porches are handsomely ornamented, and about 100 ft. from a tall campanile, the inner walls of which have been covered in parts with frescoes of religious subjects, though these are now much defaced. But the most remarkable memorial of the middle ages that exists in all this district is the monastery of Sumelas, which is situated about 25 m. from Trebizond, at the side of a rocky glen, at a height of 4000 ft. above the sea. Its position is most extraordinary, for it occupies a cavern in the middle of the face of a perpendicular cliff 1000 ft. high, where the white buildings offer a marked contrast to the brown rock which forms their setting. It is approached by a zigzag path at the side of the cliff, from which a flight of stone steps and a wooden staircase give access to the monastery. The valley below is filled with the richest vegetation, the undergrowth being largely composed of azaleas and rhododendrons. An antiquity of 1500 years is claimed for the foundation of the monastery, but it is certain that the first person who raised it to importance was the emperor Alexius Comnenus III. of Trebizond; he rebuilt it in 1360, and richly endowed it. The golden bull of that emperor, which became thenceforth the charter of its foundation, is still preserved; it is one of the finest specimens of such documents, and contains portraits of Alexius himself and his queen. The monastery also possesses the firman of Mahommed II. by which he accorded his protection to the monks when he became master of the country.
Bibliography. J. Ph. Fallmerayer, Geschichte des Kaiserthums von Trapezunt (Munich, 1827); also Fragmente aus dem Orient, vol. i. (Stuttgart, 1845); C. Texier, Asie Mineure (Paris, 1862); C. Texier and R. P. Pullan, Byzantine Architecture (London, 1864); G. Finlay, History of Greece, vol. iv. (Oxford, 1877); H. F. Tozer, Turkish Armenia and Eastern Asia Minor (London, 1881). (H. F. T.)
TREBLE (a doublet of "triple", three-fold, from Lat. triplus, triple; cf. "double" from duplus), the term applies, in music, to the high or acute part of the musical system, as opposed to and distinguished from "bass," the lower or grave part. The middle C is the practical division between the parts. The word is also used as equivalent to the "soprano" voice, the highest pitch or range of the human voice, but generally it is confined to a boy's voice of this quality, "soprano" being used of the corresponding female voice. The treble-clef is the G-clef on the second line. The origin of this application of the term "treble," triplus threefold, to the highest voice or part is due to the fact that in the early plain-song the chief melody was given to the tenor, the second part to the alto (discantus) and where a third part (triplum) was added it was assigned to the highest voice, the soprano or treble.
TRÉBUCHET, a medieval siege engine, employed either to batter masonry or to throw projectiles over walls. It was developed from the post-classical Roman onager (wild ass), which derived its name from the kicking action of the machine. It consisted of a frame placed on the ground to which a vertical frame of solid timber was rigidly fixed at its front end; through the vertical frame ran an axle, which had a single stout spoke. On the extremity of the spoke was a cup to receive the projectile. In action the spoke was forced down, against the tension of twisted ropes or other springs, by a windlass, and then suddenly released. The spoke thus kicked the crosspiece of the vertical frame, and the projectile at its extreme end was shot forward. In the trébuchet the means of propulsion was a counter-weight. The axle which was near the top of a high strutted vertical frame served as the bridge of a balance, the shorter arm of which carried the counter-weight and the longer arm the carrier for the shot. An alternative name for the trébuchet is the mangonel (mangonneau).
TREBULA, the name of five ancient towns in Italy. (1) Trebula in Samnium, a town of the Caraceni, on the left bank of the Sangro, some 20 m. below Castel di Sangro; the church of the Madonna degli Spineti near Quadri marks the site. It appears to have been a municipium, but we only know of its existence in Hadrian's time. (2) Trebula in Campania, between Saticula and Suessula. The site is probably identical with the hills bearing the modern name Tripaola (about 1000 ft. above sea level) above the entrance to the valley of Maddaloni. It is possibly this Trebula the citizens of which received Latin rights in 303 B.C. Its territory extended as far as the Via Appia, and its place was taken in imperial times by the Vicus Novanensis, on the road itself, near Suessula. (3) Trebula Balliensis (mod. Treglia), also in Campania, 22 m. north of Capua, in the mountains, about 1000 ft. above sea-level. It revolted to Hannibal and was reduced to obedience by Fabius. Remains of walls, aqueduct and tombs exist. Its territory was mentioned in the projected distributions of land in Cicero's time: and its wine was well thought of under Nero. It was a municipium. (4) Trebula Mutuesca in the Sabine country, 2 m.
