Editing John of Brienne (section)

== Emperor of Constantinople ==

=== Election ===

[[File:Marie of Brienne.jpg|right|thumb|alt=See caption|Seal of John's daughter [[Marie of Brienne|Marie]], who became [[Latin empress]] by marriage to her father's co-emperor, Baldwin II]]

The [[Latin emperor of Constantinople]], [[Robert I, Latin Emperor|Robert I]], died in January 1228.{{sfn|Lock|1995|p=62}} His brother [[Baldwin II, Latin Emperor|Baldwin II]] succeeded him, but a regent was needed to rule the Latin Empire since Baldwin was ten years old.{{sfn|Lock|1995|p=62}} [[Ivan Asen II of Bulgaria]] was willing to accept the regency, but the barons of the Latin Empire suspected that he wanted to unite the Latin Empire with [[Second Bulgarian Empire|Bulgaria]].{{sfn|Perry|2013|p=150}} They offered the imperial crown instead to John, an ally of the Holy See.{{sfn|Perry|2013|p=150}}

After months of negotiation, John and the envoys from the Latin Empire signed a treaty in Perugia which Gregory IX confirmed on 9 April 1229.{{sfn|Lock|1995|p=63}}{{sfn|Perry|2013|p=151}} John was elected emperor of the Latin Empire for life as senior co-ruler with Baldwin II, who married John's daughter [[Marie of Brienne|Marie]].{{sfn|Lock|1995|p=63}}{{sfn|Perry|2013|p=151}} The treaty also prescribed that although Baldwin would rule the Latin lands in Asia Minor when he was 20 years old, he would become sole emperor only after John's death.{{sfn|Lock|1995|p=63}}{{sfn|Perry|2013|p=151}} John also stipulated that his sons would inherit [[Epirus]] and [[Macedonia (region)|Macedonia]], but the two regions still belonged to the [[emperor of Thessalonica]], [[Theodore Doukas]].{{sfn|Lock|1995|p=63}}

After signing the treaty, John returned to Sulmona.{{sfn|Perry|2013|p=147}} According to the contemporary [[Matthew Paris]], he allowed his soldiers to plunder nearby monasteries to obtain money.{{sfn|Perry|2013|p=147}} John lifted the siege of Sulmona in early 1229 to join Cardinal Pelagius, who launched a campaign against [[Capua]].{{sfn|Perry|2013|p=148}} Frederick II (who had crowned himself king of Jerusalem in the [[Church of the Holy Sepulchre]]) returned to Italy, forcing the papal troops to withdraw.{{sfn|Runciman|1989|p=189}}{{sfn|Perry|2013|pp=148–149}}

John went to France to recruit warriors to accompany him to Constantinople.{{sfn|Perry|2013|p=152}} Gregory IX did not proclaim John's expedition to the Latin Empire a crusade but promised papal privileges granted to crusaders to those who joined him.{{sfn|Perry|2013|p=152}} During his stay in France, John was again an intermediary between local potentates{{sfn|Perry|2013|p=153}} and signed a peace treaty between [[Louis IX of France]] and [[Hugh X of Lusignan]].{{sfn|Perry|2013|p=153}} He returned to Italy in late 1230.{{sfn|Perry|2013|p=154}} John's envoys signed a treaty with [[Jacopo Tiepolo]], the [[doge of Venice]], who agreed to transport him and his retinue of 500 knights and 5,000 commoners to Constantinople in return for John's confirmation of Venetian possessions and privileges in the Latin Empire.{{sfn|Perry|2013|p=155}} Shortly after John left for Constantinople in August, Gregory IX acknowledged Frederick II's claim to the Kingdom of Jerusalem.{{sfn|Perry|2013|p=156}}

=== Rule ===
John was crowned emperor in [[Hagia Sophia]] in autumn 1231;{{sfn|Perry|2013|p=162}} by then, his territory was limited to Constantinople and its vicinity.{{sfn|Lock|1995|p=65}} The Venetians urged him to wage war against the [[emperor of Nicaea]], [[John III Vatatzes]], who supported a rebellion against their rule in [[Crete]].{{sfn|Perry|2013|p=166}} According to [[Philippe Mouskes]]' ''Rhymed Chronicle'', John could make "neither war nor peace";{{sfn|Perry|2013|p=162}} because he did not invade the [[Empire of Nicaea]], most French knights who accompanied him to Constantinople returned home after his coronation.{{sfn|Perry|2013|p=162}} To strengthen the Latin Empire's financial position, [[Geoffrey II of Achaea]] (John's most powerful vassal) gave him an annual subsidy of 30,000 ''[[Hyperpyron|hyperpyra]]'' after his coronation.{{sfn|Lock|1995|p=65}}{{sfn|Perry|2013|p=166}}

Taking advantage of John III Vatatzes' invasion of [[Rhodes]], John launched a military expedition across the [[Bosphorus]] against the Empire of Nicaea in 1233.{{sfn|Perry|2013|p=172}}{{sfn|Treadgold|1997|p=723}} His three-to-four-month campaign "achieved little, or nothing"; the Latins only seized [[Pegai]], now [[Biga, Çanakkale|Biga]] in Turkey.{{sfn|Perry|2013|p=172}} With John's approval, two [[Franciscan]] and two [[Dominican Order|Dominican]] [[friar]]s wanted to mediate a truce between the Latin Empire and Nicaea in 1234 but it was never signed.{{sfn|Perry|2013|p=173}} In a letter describing their negotiations, the friars described John as a "pauper" abandoned by his mercenaries.{{sfn|Perry|2013|p=161}}

John III Vatatzes and Ivan Asen II concluded a treaty dividing the Latin Empire in early 1235.{{sfn|Treadgold|1997|p=724}} Vatatzes soon seized the last outposts of the empire in [[Anatolia|Asia Minor]] and [[Gallipoli]], and Asen occupied the Latin territories in [[Thrace]].{{sfn|Treadgold|1997|p=724}} [[Siege of Constantinople (1235)|Constantinople was besieged]] in an effort to persuade the defenders to gather in one place, enabling an invasion elsewhere.{{sfn|Perry|2013|p=174}} Although the besiegers outnumbered the defenders, John repelled all attacks on the town's walls.{{sfn|Perry|2013|p=175}} Mouskes compared him to [[Hector]], [[Roland]], [[Ogier the Dane]] and [[Judas Maccabeus]] in his ''Rhymed Chronicle'', emphasizing his bravery.{{sfn|Perry|2013|p=175}}

A Venetian fleet forced Vatatzes' naval forces to withdraw, but after the Venetians departed for home the Greeks and Bulgarians besieged Constantinople again in November 1235.{{sfn|Perry|2013|p=176}} John sent letters to European monarchs and the pope, pleading for assistance.{{sfn|Perry|2013|p=176}} Since the survival of the Latin Empire was in jeopardy, Gregory IX urged the crusaders to defend Constantinople instead of the Holy Land.{{sfn|Perry|2013|p=179}} A combined naval force from Venice, [[Republic of Genoa|Genoa]], [[Republic of Pisa|Pisa]] and Geoffrey II of Achaea broke through the blockade.{{sfn|Perry|2013|p=176}} Asen soon abandoned his alliance with Vatatzes, who was forced to lift the siege in 1236.{{sfn|Perry|2013|p=177}}

=== Death ===

According to three 13th-century authors (Matthew Paris, Salimbene di Adam and [[Bernard of Besse]]), John became a Franciscan friar before his death.{{sfn|Perry|2013|p=180}} They agree that John's declining health contributed to his conversion, but Bernard also described a recurring vision of an old man urging the emperor to join the Franciscans.{{sfn|Perry|2013|p=181}} Most 13th-century sources suggest that John died between 19 and 23 March 1237,{{sfn|Perry|2013|p=182}} the only Latin emperor to die in Constantinople.{{sfn|Perry|2013|p=182}}

According to the ''Tales of the Minstrel of Reims'', he was buried in Hagia Sophia.{{sfn|Perry|2013|p=183}} Perry wrote that John, who died as a Franciscan friar, may have been buried in the Franciscan church dedicated to Saint Francis of Assisi which was built in [[Galata]] during his reign.{{sfn|Perry|2013|p=183}} In a third theory, proposed by [[Giuseppe Gerola]], a tomb decorated with the Latin Empire coat of arms in [[Assisi]]'s [[Basilica of Saint Francis of Assisi#Lower Basilica|Lower Basilica]] may have been built for John by [[Walter VI, count of Brienne]].{{sfn|Perry|2013|p=183–185}}