Page 205

Ch. VI THE LATIN EMPIRE OF CONSTANTINOPLE 205 
Trapezuntines attacked Nicomedia, diverting Theodore from an assault on Pontic
Heraclea. Theodore did drive the Latins back across the straits, but now
David sent supplies to Constantinople, and agreed to become Henry's vassal.
During the winter of 1206 - 1207 the Latins won Pegae, Cyzicus, and Nicomedia.
In difficulty, Theodore Lascaris appealed to Ioannitsa to help him by launching
an attack on the Latins in Europe. As soon as Ioannitsa did so, and Henry
had to weaken his forces in Asia, Theodore attacked. A dash across the straits
by Henry in person saved the garrison but not the fortress of Civetot (Cibotus).
Another saved Cyzicus from a naval attack led by a Calabrese pirate, Stirione,
once admiral of Alexius III and now in Lascaris's service. The Latins chased
him out through the Dardanelles into the Aegean. A third expedition saved
Nicomedia, and a fourth rescued the survivors of a Latin force, which Lascaris
had defeated. All this time Ioannitsa was besieging Adrianople, which the
Latins could not relieve. When Lascaris proposed a two-year truce, offering
to exchange all his Latin prisoners for the right to raze the Latin fortresses
at Cyzicus and Nicomedia, Henry accepted the offer. He had nothing left in
Asia but Pegae and Charax. The truce almost fulfilled Lascaris's war aims
of the moment: to expel the Latins from Asia. Freed for a European campaign,
Henry began an advance, but lost many men in a new ambush. 
 In February 1207 Henry had married Agnes, the daughter of Boniface of Montferrat,
at a solemn ceremony in Hagia Sophia, followed by a splendid wedding feast
in the imperial palace of the Boukoleon. Now, in the summer of 1207, Henry
and Boniface conferred on the banks of the Maritsa; Boniface did homage to
Henry, and received Thessalonica from him as a fief, as he had from Baldwin.
Soon after the conference, however, Boniface was killed in a skirmish with
the Bulgarians. About the same time, Ioannitsa himself died suddenly, of
a hemorrhage of the lungs; the death was at once attributed to St. Demetrius,
defender and patron of Thessalonica. These two deaths substantially altered
the situation. 
 Ioannitsa's proper heir was his young nephew, John Asen. Too young to make
good his claim, however, he fled to Russia, and there ensued a struggle for
the throne among three rival chieftains: Slav, a relative of the royal family,
with headquarters at Melnik in the Rhodope mountains; Strez, another relative,
but the protégé of king Stephen of Serbia, with headquarters
in the strong Vardar valley fortress of Prosek; and Boril, Ioannitsa's sister's
son, who married his uncle's Kuman widow and seized Tirnovo, the capital.