(or baioulos) and described him as a "great babbler" in his works, without mentioning his name. He studied grammar (that is Attic Greek), poetry, rhetoric, logic, mathematics, astronomy, geometry and music for three years. His grammatical studies raised his lifelong interest in words with multiple meaning and in etymologies. The young Theodore was captivated by the orations of Demosthenes and Hermogenes of Tarsus. He also held theologian Gregory of Nazianzus in high esteem. His tutor mocked him for "philosophizing" and urged Theodore to spend more time with military and diplomatic studies. Theodore was a passionate hunter and polo player with remarkable riding skills. Negotiations over Theodore's marriage with Elena of Bulgaria began shortly after the Battle of Klokotnitsa, where Elena's father, Emperor (or Tzar) Ivan Asen II of Bulgaria, inflicted a crushing defeat on the Emperor of Thessalonica and ruler of Epirus, Theodore Komnenos Doukas. The battle weakened Epirus–Thessalonica, Nicaea's western rival for the revival of the Byzantine Empire, and made Bulgaria the dominant power of the Balkan Peninsula. The marriage of Theodore and Elena sealed their fathers' alliance against the Latin Empire of Constantinople in 1235. In the same year, Bulgarian and Nicaean troops laid siege to Constantinople, but could not capture the city. In 1237, Ivan Asen then reversed his position, allying himself with the Latins to stop Nicaean expansion in Thrace, only to return to his alliance with Nicaea before the end of the year. His father-in-law's tactical moves convinced Theodore that he could not fully trust the Bulgarians—a view he held for the rest of his life. Theodore approached a most renowned teacher, Nikephoros Blemmydes, to take philosophy classes from him. Blemmydes was the hegumenos (abbot) of a monastery at Ephesus. Theodore attended his philosophy classes while he was staying in his father's winter palace at nearby Nymphaion. Blemmydes' zealous Aristotelianism had a strong impact on Theodore, who often mentioned Aristotelian notions, like potentiality and actuality, in his writings. Blemmydes was accused of embezzlement by one of his students early in the 1240s. Although Vatatzes' intervention saved him from imprisonment, he abandoned teaching. Theodore continued to visit Blemmydes regularly and maintained a correspondence with him. A young scholar, George Akropolites, replaced Blemmydes as Theodore's principal tutor. Born in Constantinople, Akropolites had firsthand experience with the Latin rule in the city. He completed Theodore's education in logic and mathematics. Theodore's mother died late in 1239. Vatatzes remarried