1222 Theodore of Epirus takes possession of the Lombard kingdom of Thessalonica. Defeat of Robert at Serres.
1223-1224 Robert invades Nicæa with many losses. Revolt of the Greeks in Hadrianopolis. Theodore of Epirus takes the city.
1228 Death of Robert. His young brother, Baldwin II, succeeds. Jean de Brienne, titular king of Jerusalem, elected guardian and colleague. The empire is attacked by Joannes Vatatzes of Nicæa and John Asan, king of Bulgaria.
1233 Jean de Brienne routed in Bithynia.
1234 Alliance between Vatatzes and Asan to attack Constantinople. They ravage the whole Latin Empire.
1236 Danger to Constantinople averted by help from the Venetians and Geoffrey of Achaia.
1237 Death of Jean de Brienne. The Bulgarian king abandons Nicæa and makes alliance with Latins. Baldwin visits western Europe to obtain help. Louis IX of France gives pecuniary assistance.
1240 Baldwin with his new army attacks Nicæa and obtains some advantage.
1243 Baldwin makes alliance with Seljuk Turks, but in spite of this is compelled to 1245 revisit western Europe for assistance.
1259 On the accession of Michael Palæologus, the Nicæan Empire attacks the Latin Empire.