1225 Peace with the Latins. Conspiracy of Nestongos.
1233 Defeat of the Latins by Joannes in Bithynia. Naval campaign to obtain sovereignty of the sea. The Greek fleets driven back to Asia by the Venetian, Marino Sanuti.
1234 Alliance of Joannes Vatatzes and Asan of Bulgaria against Baldwin II. Vatatzes reduces the empire of Thessalonica to a despotat (despotat of Epirus).
1236 Attack of the allies on Constantinople unsuccessful.
1237 Asan breaks the alliance as Constantinople is about to be attacked the second time.
1241 On the death of John Asan of Bulgaria, Vatatzes begins to assert his supremacy over the emperor of Thessalonica.
1242 Joannes Comnenus, the Thessalonian emperor, reduced to rank of despot by Vatatzes. Alliance with the sultan of Iconium to resist threatened invasion of Mongols who have already destroyed the Seljuk empire.
1245 Joannes Vatatzes reconquers Byzantine dominions in Thrace from the infant king Michael of Bulgaria.
1246 Vatatzes unites despotat of Epirus to the empire.
1251-1253 War with Michael II, despot of Epirus, ending in a peace ceding some Thracian territory to Vatatzes.