Turkish warships launched in 1425 by Ottoman…

The Hongxi Emperor orders that the capital be moved back to Nanjing from Beijing (which had been made the capital by the Yongle Emperor in 1421).

However, he dies, probably of a heart attack, a month later in May 1425.

His son had been declared heir apparent and becomes the Xuande Emperor at age twenty-six.

Although the Hongxi Emperor had had a short reign, he is credited with reforms that made lasting improvements, and his liberal policies are continued by his son.

Vasily II is the youngest son of Vasily I of Moscow by Sophia of Lithuania, the only daughter of Vytautas the Great, and the only son to survive his father (his elder brother Ivan had died in 1417 at the age of twenty-two).

On his father's death at fifty-four in 1425, ten-year-old Vasily is proclaimed Grand Duke.

His mother acts as a regent.

His uncle, Yuri of Zvenigorod (Prince of Galich-Mersky), and his two sons, Vasily the Cross-Eyed and Dmitry Shemyaka, seize on the opportunity to advance their own claims to the throne.

These claims are based on the Testament of Dmitri Donskoi, Yuri's father and Vasily's grandfather, who had stated that if Vasily I died Yuri would succeed his appanage.

However, Dmitri had written the testament when Vasily I had no children of his own, and it might be argued that this provision had been made only for the case of Vasily's childless death.

Vasily's claim is supported by Vytautas, his maternal grandfather, and by the boyars.

Philippa has acted as Regent of the three Kalmar Union kingdoms from 1423 to 1425 during her husband's stay abroad.

Among other acts, she has made a treaty with some members of the Hansa states concerning the validity of the coin-system.

Manuel II Palaiologos has retired to a monastery, where he die at seventy-five on June 21, 1425, leaving numerous literary works (many of which survive).

The well-educated emperor is the author of numerous works of varied character, including letters, poems, a Saint's Life, treatises on theology and rhetoric, and an epitaph for his brother Theodore I Palaiologos and a ‘mirror for prince’ (Latin: specula principum or rather, principum specula) for his son and heir John VIII.

This mirror of prince has special value, because it is the last sample of this literary genre bequeathed to us by the imperial Greeks.

John is sole emperor from July 1425, ruling the area immediately surrounding Constantinople, while his brothers govern remnants of the fragmented empire in the Greek Peloponnese and in the districts on the Black Sea.

Murad has distributed most of his conquests to members of the Kapikulu force, occasionally as timars but more often as tax farms (iltizams), so that the treasury can obtain the money it needs to maintain the Janissary army entirely on a salaried basis.

In addition, in order to man the new force, Murad has developed the devsirme system by which promising Christian youths are drafted from the Balkan provinces for conversion to Islam and life service to the sultan.

Subject to strict rules, including celibacy, they are organized into three unequal divisions (cemaat, bölükhalki, segban) and commanded by an aga.

By 1425, Murad has eliminated his rivals, has reestablished Ottoman rule over the Turkmen principalities of western Anatolia, and has once again forced Constantinople to pay tribute.

He now turns his attention to the Balkans.

Murad pursues a policy of caution in Anatolia because of the westward advance of the Timurid Shahrukh, who poses as protector of the Turkmen principalities.

The Ottomans have gained suzerainty over the Turkmen rulers in the Çorum-Amasya region and in western Anatolia, but …

…the principality of Karaman, which through its alliances with the Balkan Christian rulers is a major threat to the Ottomans, is left autonomous though tributary, as is …

…Candar (Jandar), so as not to excite the renewed fears of Timur's successors in the East.

The Beylik of Smyrna had been incorporated into the Ottoman Empire for the first time in 1390, and after the violently destructive passage of Timur in Anatolia in 1402 and the ensuing period of troubles that lasted until 1425, its territories again become part of the Ottoman realm, this time definitively.

Greek influence is so strong in the area that the Turks call the city "Smyrna of the infidels" (Gavur İzmir).

The city had several times been ravaged by the Turks, and had become quite ruinous when the Nicaean emperor John III Doukas Vatatzes rebuilt it about 1222.

Ibn Batuta found it still in great part a ruin when the homonymous chieftain of the Beylik of Aydın had conquered it about 1330 and made his son Umur governor; it became the port of the emirate.

Soon afterwards, the Knights of Saint John established themselves in the town but failed to conquer the citadel.

…at Epirus in western Greece.

The Serbian King Stefan Uroš IV Dušan, taking advantage of the civil war between John V Palaiologos and John VI Kantakouzenos, had conquered Epirus in 1348, with a number of Albanian mercenaries assisting him.It is during this time that an Albanian presence in Epirus is first mentioned.

The imperial authorities in Constantinople had soon reestablished a measure of control by making the Despotate of Epirus a vassal state, but meanwhile Albanian clans had invaded, seized most of the region, and founded two local, short-lived entities, centered in Arta (1358–1416) and Gjirokastër (1386–1411) by the Losha and Zenebishi clans, respectively.

Only the city of Ioannina had remained under Greek control during this time.

Although Albanian clans had gained control of most of the region of Epirus by 1366-7, they had not succeeded any Greek or Serbian central authority in the region but have remained divided in clans.

Ioannina had become a center of Greek resistance, and the Greeks of Ioannina had offered power to three foreign rulers during this time, beginning with Thomas II Preljubović (1367–1384), followed by Esau de' Buondelmonti (1385–1411), and finally Carlo I Tocco (1411–1429).

The latter finally succeeds in ending the rule of the Albanian clans and unifying Epirus.