Theodore sent letters to the Greeks under the Latins' rule to inform them of his triumph and to urge them to rise up against the "Latin dogs". However, he had only won a Pyrrhic victory, because his best troopshis Latin mercenariesperished in the battlefield. Emperor Henry led his army across the Bosporus and routed Theodore's troops on the Rhyndakos River on 15October 1211. Henry captured Nymphaion and Pergamon. In a circular letter sent to the European monarchs early in 1212, he boasted of having subjugated the Greeks as far as the Seljuq frontier, save the garrisons of some fortresses. Henry had to end his military campaign because he did not have enough troops to garrison the captured fortresses. The two emperors made peace between 1212 and 1214 The peace confirmed the Latins' possession of the Troad region. The Latins also seized some strategically important Bithynian fortresses, taking control of the roads between the northern and southern territories of Theodore's realm. Theodore adopted an intensive fortification program. New fortresses were built, and the old fortresses' walls were restored. He also urged local officials to settle colonists around the new forts, granting arable lands to them.