|1235||Siege of Constantinople||★ ★ ★ ★ ★|
|Outcome:||A joint Bulgarian-Nicaean siege on the capital of the Latin Empire||1235|
|War & Enemy:||
|The Battlefield|| Location:
| Modern Country:
|The Byzantines(emperor: John III Doukas Vatatzes)||The Enemies|
|Commander:||Emperor John III Doukas Vatatzes||Regent John of Brienne|
|Background story:||After Robert of Courtenay died in 1228, a new regency under John of Brienne was set up. After the disastrous Epirote defeat by the Bulgarians at the Battle of Klokotnitsa, the Epirote threat to the Latin Empire was removed, only to be replaced by Nicaea, which . Emperor John III Doukas Vatatzes of Nicaea after his victory at Poemanenum took back most of the Latin possessions in Asia Minor and continued his successes acquiring territories in Greece.
Later he concluded an alliance with Bulgaria, which in 1235 resulted in joint campaign against the Latin Empire.
The Byzantine forces under the command of John III Vatatzes and the Bulgarians under the leadership of Tsar Ivan Asen II laid siege to the capital by land and sea. The Venetian Duke of the Archipelago Angelo Sanudo sent a naval squadron and the great Latin warrior John of Brienne was able to lead a brilliant counter-offensive to repulse the allies and break the siege.
John III Doukas Vatatzes
The allies retreated in the autumn because of the incoming winter. Ivan Asen II and Vatatzes agreed to continue the siege in the next year but the Bulgarian Emperor refused to send troops. With the death of John of Brienne in 1237 the Bulgarians broke the treaty with Vatatzes because of the possibility that Ivan Asen II could become a regent of the Latin Empire.
|Aftermath:||The siege was unsuccessful and a treaty was signed after a new intervention by Sanudo. The Greek successes continued in the following years and gradually the Latin Empire was limited within the walls of Constantinople.|