The Byzantine Empire: eleventh to fifteenth century
to establish himself in the Meander valley. In this case, according to Choni-
ates, Theodore Laskaris came to an agreement with Keyh
¨
usrev and granted
him a portion of the territory which included Chonai (Honas) and Phrygian
Laodikeia (Denizli).
97
Despite these agreements, the Turks, intent on captur-
ing the coastal regions, took advantage of the upheavals and seized a number
of fortresses, including Attaleia (Antalya).
98
In addition, at the mediation of
Venice, Keyh
¨
usrev entered into a secret alliance with Henry in 1209,
99
and tried
to elicit support among the Byzantines by championing the cause of Alexios
III Angelos, Theodore’s father-in-law, who had returned from the west and
had taken refuge with the sultan. Hostilities continued round Antioch on the
Meander with losses for the Nicaeans, but the sultan’s defeat and death in
1211 removed for the time being the pressure on the eastern front, thus giv-
ing Theodore the opportunity to turn his attentions to the Latins. After the
Byzantine victory on the Rhyndakos(Orhaneli) river in that year, Henry moved
on to Pergamon (Bergama) and Nymphaion (Nif, now Kemalpas¸azade). How-
ever, subsequent hostilities and skirmishes betweenthe two forces proved both
indecisive and draining, and in 1214 a treaty was concluded at Nymphaion
between the two empires.
100
Relations between Nicaea and Constantino-
ple remained friendly after Henry’s death and in 1216 Theodore married
Henry’s niece as his third wife. Three years later, Theodore renewed the
former extensive trade privileges to the Venetians operating in the empire of
Nicaea.
101
Thepeaceful relations with the Latins left Theodorefreeto tackle the empire
of Trebizond which owed allegiance to the Latin emperor of Constantinople.
In that year Theodore annexed all their lands west of Sinope (Sinop), including
Herakleia (Ere
˘
gli) and Amastris (Amasra).
102
This provoked the Seljuk ruler,
Keykavus I (1210–20). He attacked Trebizond (Trabzon), seized Sinope (1215–
16), captured AlexiosKomnenos and reinstalled him on the throne of Trebizond
as his vassal. With Sinope as their naval base, the Seljuks were gradually to
develop into an important maritime element in the Black Sea.
103
97 Manuel Mavrozomes (Choniates, Historia,pp.626, 638; Magoulias, pp. 343, 350).
98 Akropolites, Opera, i,§9,p.15 (Macrides, p. 129); cf. Choniates, Historia,p.640 (Magou-
lias, p. 351), who states that the Turks failed to capture the city.
99 E. Gerland, Geschichte des lateinischen Kaiserreiches von Konstantinople, I: Geschichte der
Kaiser Baldwin I und Heinrich 1204–16 (Homburg v.d. H
¨
ohe, 1905), pp. 210 ff.
100 Akropolites, Opera, i,§15,pp.27–8 (Macrides, pp. 148–9).
101 August 1219, Tafel and Thomas, Urkunden, ii,no.252,pp.205–7; D. Jacoby, ‘The Econ-
omy of Latin Constantinople, 1204–61’, in Urbs Capta: the Fourth Crusade and its Conse-
quences/La IVe croisade et ses consequences, ed. A. E. Laiou (Paris, 2005), pp. 206–7.
102 Akropolites,Opera, i,§11,p.18 (Macrides, p. 132);
Ahrweiler, Mer,p.306 n. 6.
103 Ahrweiler, Mer,p.307 n. 4.
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