Still possessing a powerful network of allies, John VII never surrendered his claim to be the legitimate emperor, and the tense relationship between him and his uncle brought the empire close to civil war several times.

Manuel left the city in 1399 to travel around Western Europe in search for military aid, and entrusted John VII with serving as regent in Constantinople, overseeing its defense.

Despite allegations of conspiring with the Ottomans, John VII held the city loyally for the entire duration of Manuel's three and a half years-long journey, refusing to surrender it to Bayezid.

In the aftermath of this battle, John VII negotiated a favourable treaty with one of Bayezid's sons, Süleyman Çelebi, which ensured that the important city of Thessalonica, lost to the Ottomans in 1387 due to the actions of Manuel, was returned to imperial control.

This feud proved to be brief, as they were reconciled a few months later and a new agreement was made, in which John VII was allowed to take possession of Thessalonica and was acknowledged with the full imperial title.

The Thessalonians considered him an able ruler, and his work with local church affairs and improving the city's defensive structures garnered him a positive remembrance.

[6][9][11] Imprisoned with his family in the Prison of Anemas in Constantinople,[15] Andronikos escaped in July 1376, together with his wife and son, to Galata, a colony of the Republic of Genoa on the other side of the Golden Horn, where he was enthusiastically received by the Genoese.

The Genoese preferred Andronikos over John V, due to the latter having recently granted the island of Tenedos to their rival, the Republic of Venice, thus hurting their commercial interests.

[1] From his position as junior emperor, John VII received support from the Ottoman Empire, especially from the time of Bayezid I's accession (1389) onwards, and from the Genoese.

[20] When Manuel was away campaigning in Anatolia in 1390, John VII, twenty years old, seized the moment and proclaimed himself sole emperor,[20] laying siege to Constantinople.

[23] In addition to his external allies, a large percentage of the population within Constantinople also supported John VII, and might even have approved of subtle Ottoman intervention in the succession.

Ignatius of Smolensk, eyewitness to the event, wrote that the soldiers in John VII's service shouted the acclamation "Polla ta eti Andronikou!

[c] It is possible that John VII changed his name to Andronikos upon his father's death in 1385 to honour his memory,[25] or adopted it only in 1390, in order to avoid confusion and facilitate his usurpation of the throne.

[28] John VII never gave up his claim to be emperor, and continued to be a powerful political player in the Byzantine Empire for years following his deposition.

[32] John VII's hopes of claiming the throne continued to be supported by Bayezid I, who saw him as a more promising candidate than the staunchly anti-Ottoman Manuel II.

[31] In addition to his backing by certain aristocrats and his international allies, there was also a faction within Constantinople, mainly composed of commoners, who wished to restore John VII as senior emperor, as late as 1399.

As John VII had been constitutionally invested with the right to succeed to the throne in 1381, they saw him as the legitimate heir, not Manuel, who was viewed as a usurper more interested in his own power than anything else.

[33] Encouraged by the French knight Boucicaut, who had been placed as the leader of Constantinople's defense and who had good relations with both John VII and Manuel, the two emperors reached an agreement meant to end their dynastic feud in 1399.

The only textual records that survive of John's activities in Constantinople are treaties with the Venetians and Genose, and documentation of his decision to depose Patriarch Matthew I.

[37] On 1 June 1402, as the siege was escalating, John VII sent a letter to Henry IV of England, writing of the urgent danger threatening Constantinople.

Bayezid's defeat and capture at the Battle of Ankara on 20 July 1402, and the subsequent period of Ottoman civil war it sparked, ended the siege of Constantinople and saved the city.

[44] The Ottoman defeat at Ankara was used by John to negotiate a treaty with one of Bayezid I's sons, Süleyman Çelebi, in which the city of Thessalonica, as well as substantial territories in Thrace and Macedonia, were returned to the Byzantine Empire.

Since he knew that John VII could no longer rely on the support of the Ottomans, Manuel attempted to completely exclude him from the imperial hierarchy, stripping him of the title basileus and depriving him of his promised lands in Selymbria and Thessalonica.

[48] It is doubtful that such an agreement was ever made, especially since John proved himself to be loyal for the duration of his tenure as regent and concluded a highly favourable treaty with the Ottoman prince Süleyman Çelebi.

[53] The transfer of Thessalonica from Ottoman control to the Byzantines was overseen by Manuel's confidant, Demetrios Laskaris Leontares, who per the agreement between the two emperors handed it over to John VII.

[54] Though no known surviving copies exist, a detailed oath was drawn up between Manuel and John, which decided upon a well-defined border between the empires of Constantinople and Thessalonica.

According to Symeon of Thessalonica, John VII "fortified [the city] on all sides with triremes and outer walls" and "adorned [it] with good regulations and institutions".

That the Thessalonians had enjoyed the rule of a leader with a rebellious past, who just like Manuel bore the title basileus, had probably only stimulated the city's separatist tendencies.

[53] A praiseful passage in a eulogy of John, from the Synodikon of Thessalonica, reads:[62] For our emperor John Palaiologos fought almost on his knees fiercely and courageously in defense of the Romans at a time when foreign peoples were leaning towards us [...] and when an unspeakably most powerful billow which had been raised and was threatening to destroy everything, and released the emperor from slavery and secured our safety by all possible means.

[68]Other eulogies, as well as a similarly praiseful monody by the contemporary Byzantine author Theodore Potamios, almost give the impression that a cult of John VII was beginning to develop in Thessalonica.