Ulrich of Celje, a Slovenian magnate and…

Shemyaka has continued to plot against his cousin despite several peace treaties.

He had suffered a series of defeats in 1450 and 1452 that force him to seek refuge in Novgorod.

Here, on July 17, 1453, he was poisoned while eating a dinner of chicken in the Gorodishche, the princely compound south of the Market side of the city, his cook having been bribed by Muscovite agents.

Delighted at the news, Vasily II ennobles a herald who had first brought him the message of Shemyaka's death.

Nikolai Karamzin will famously write in his history that the grand prince showed "indecent joy" at the news of his rival's untimely demise.

Galicia, meanwhile, is rejoined to Muscovy.

Andrea del Castagno increasingly accentuates the elements of movement and vigorous action in his later works.

The extreme foreshortening of the image of the Holy Trinity in the fresco Trinity with St. Jerome and Two Holy Women, executed around 1453 for Santissima Annunziata, in Florence, exemplifies the ways in which Castagno frequently manipulates perspective to underscore the expression and content of a painting.

Pope Nicholas’s first concern is practical: the reinforcement of the city's fortifications, the cleaning and even paving of some main streets and restoring the water supply.

Ancient Rome’s magnificent array of aqueducts having been destroyed by the hands of sixth-century invaders, Romans have depended on wells and cisterns for their water, and the poor dip their water from the Tiber.

The Aqua Virgo aqueduct, originally constructed by Agrippa, is restored by Nicholas to empty into the predecessor of the Trevi Fountain, a simple basin designed by Leon Battista Alberti.

Nicholas, his heart set on the rebuilding the Vatican, the Borgo district, and St. Peter's Basilica, which is to be the focus of the reborn glories of the papacy, manages to pull down part of the ancient basilica, make some alterations to the Lateran Palace (of which some frescoes by Fra Angelico bear witness), and lay up two thousand five hundred and twenty-two cartloads of marble from the dilapidated Colosseum for use in the later constructions.

In undertaking these works Nicholas is moved "to strengthen the weak faith of the populace by the greatness of that which it sees."

The Roman populace, however, appreciates neither his motives nor their results: a formidable conspiracy for the overthrow of the papal government under the leadership of Stefano Porcaro had been discovered and crushed in 1452.

The Revolt of Ghent and the Battle of Gavere: Philip the Good’s Decisive Victory (1453)

During the winter of 1452–1453, forces from rebellious Ghent rampaged across the Flemish countryside, pillaging Burgundian territories without significant resistance from Philip the Good, Duke of Burgundy. In one particularly audacious operation, Ghent’s troops nearly destroyed the entire Burgundian winter gunpowder supply at Lille, prevented only by the vigilance of an alert guard who extinguished a fuse moments before disaster.

Seeking to preserve the economic value of prosperous Ghent, Philip initially pursued negotiations, which the city adamantly refused. In response, Philip resolved on a decisive military campaign, launching it officially on June 18, 1453. Coordinated Burgundian forces advanced strategically toward Ghent: a fleet navigated up the Scheldt from Sluis and Antwerp, while Philip marched from Lille, systematically capturing Ghent’s outlying strongholds.

Philip’s campaign opened with the rapid and brutal capture of Schendelbeke on June 27, following two days of intensive artillery bombardment. Subsequently, between July 2 and July 5, Burgundian guns reduced Poeke Castle to rubble, although this victory came at the cost of the life of Burgundian hero and Knight of the Golden Fleece, Jacques de Lalaing. Philip displayed ruthless discipline: Ghent’s captured defenders were hanged after each victory, with 104 executed in Schendelbeke alone.

On July 18, 1453, Burgundian forces reached Gavere Castle, the final barrier before Ghent itself. After five days of relentless artillery bombardment, the English mercenary captain John Fox, commanding Ghent's defenses at Gavere, escaped to Ghent by deceiving Burgundian guards with stolen uniforms and knowledge of the Burgundian password. His unexpected arrival in Ghent early on July 23 caused widespread panic, leading city authorities to compel around 25,000 residents—under threat of execution—to launch an ill-prepared relief expedition.

The Burgundians, anticipating such an attempt, had carefully selected terrain between Semmerzake and Gavere, positioning their troops strategically along the wooded banks of the Leebeek valley. When Ghent’s relief force confronted the Burgundians, they watched as John Fox and his mercenaries dramatically defected back to Philip’s side. Already shaken by this betrayal, the Ghent militia collapsed in panic after an accidental explosion among their own artillery. The battle quickly descended into slaughter, with Ghent losing between 16,000 and 20,000 men. Only the desperate, final resistance of about a thousand Ghent militia prevented an immediate Burgundian march into the defenseless city. Notably, during these closing stages of combat, Philip himself entered the fray and was wounded by one of the last Ghent defenders.

Following this devastating defeat, Ghent swiftly surrendered, culminating in the humiliating Peace of Gavere. This treaty decisively ended Ghent’s revolt and significantly advanced Philip the Good’s centralization of Burgundian power at the expense of urban autonomy. Moreover, Philip’s victorious campaign reinforced the transformative impact of modern gunpowder artillery on late medieval warfare, marking a critical step toward centralized royal authority and the definitive weakening of civic independence in Atlantic West Europe.

Henry’s queen, Margaret of Anjou, strong-willed in contrast to her feeble husband, has established an ascendancy at the court, together with the powerful Beaufort family, headed by Edmond Beaufort, Duke of Somerset.

Cade’s rebellion, though unsuccessful in its aims, had eroded royal authority, enabling Richard, Duke of York, to return in autumn 1450 from his new post as Lieutenant of Ireland to England, where he had been recognized as heir to the childless King Henry VI.

He had marched on London, demanding Somerset's removal and reform of the government.

At this stage, few of the nobles support such drastic action, and York had been forced to submit to superior force at Blackheath.

He has been imprisoned for much of 1452 and 1453 but is released after swearing not to take arms against the court.

The loss of Bordeaux in 1453 has turned the English towards the Yorkists and against the Lancastrian Beaufort family.

The increasing discord at court is mirrored in the country as a whole, where noble families engage in private feuds and show increasing disrespect for the royal authority and for the courts of law.

The Percy-Neville feud is the best-known of these private wars, but others are being conducted freely.

In many cases, they are fought between old-established families, and formerly minor nobility raised in power and influence by Henry IV in the aftermath of the rebellions against him.

The quarrel between the Percys—long the Earls of Northumberland—and the comparatively upstart Nevilles follows this pattern, as does the feud between the Courtenays and Bonvilles in Cornwall and Devon.

A factor in these feuds is the presence of large numbers of soldiers discharged from the English armies that had been defeated in France.

Nobles engage many of these to mount raids, or to pack courts of justice with their supporters, intimidating suitors, witnesses and judges.

This growing civil discontent, the abundance of feuding nobles with private armies, and corruption in Henry VI's court form a political climate ripe for civil war.

With the king so easily manipulated, power rests with those closest to him at court, in other words Somerset and the Lancastrian faction.

Richard and the Yorkist faction, who tend to be physically placed further away from the seat of power, find their power slowly being stripped away.

Royal power also starts to slip, as Henry is persuaded to grant many royal lands and estates to the Lancastrians.

Margaret’s position is greatly reinforced in October 1453 by the birth of a son, Edward, whose status as royal heir presents a problem for the Yorkist claim.

However, Henry suffers the first of several bouts of complete mental collapse, during which he fails even to recognize his newborn son.

John Dunstaple (or Dunstable) and his near-contemporary, Leonel Power, compose mass-ordinary cycles, their movements usually related by such musical themes as a common head motive or a cantus firmus (“fixed song”).

The cantus firmi, originally composed or preexisting melodies on which a polyphonic composition is based, include borrowed plainsong melodies and secular tunes.

The innovative Dunstaple bases his sensuous, constant harmony on interval of the third and the sixth.

One of the most famous composers active in the early fifteenth century, Dunstaple, also known as a mathematician and astrologer, is widely influential, not only in England but on the continent, especially in the developing style of the Burgundian School.

Very few manuscript sources of Dunstaple's works survived in England, as is similarly the case for other fifteenth century-composers.

Although England at this time is a center of musical activity, in some respects exceeding even the output of the Burgundian School, almost all of the music will be destroyed between 1536 and 1540 during the Dissolution of the Monasteries under Henry VIII.

An influence on, and influenced by, the great composer Guillaume Dufay, Dunstaple dies at about seventy-three on December 24, 1453, leaving a body of work consisting chiefly of Latin church music, including motets and settings of sections of the Mass.

His few three-part chansons are distinguished by free melodic invention with smooth contrapuntal writing and consonant harmonies.

Dunstaple is probably the most influential English composer of all time, yet he remains an enigma: his complete works were not published until the quincentenary of his death in 1953, but even since then works have been added and subtracted from his oeuvre; we know very little of his life and nothing of his undoubted learning; we can only make an educated guess at most of the chronology of the small amount of music that has come down to us; and we understand little of his style—why he wrote as he did, what artistic or technical principles guided his composing, how his music was performed, or why it was so influential.

Mehmed has devoted the utmost care to all the necessary diplomatic and military preparations for the capture of Constantinople.

To keep Venice and Hungary neutral, he signs peace treaties favorable to them.

The Venetians in Constantinople, and a Genoese contingent commanded by Giovanni Giustiniani, wholeheartedly cooperate in the defense of the city, however, when the crisis comes.

Constantine commands an army of only ten thousand men, left as the city's sole defenders after the Turkish navy drives off an assisting Venetian naval fleet and erects a blockade.

Mehmed lays siege to the walls in April 1453.

A chain that the Greeks have thrown across the mouth of the Golden Horn obstructs his ships.

The ships are therefore dragged overland to the harbor from the seaward side, bypassing the defenses.

The Sultan's heavy artillery, fifty-six giant, stone-ball-firing cannons and twelve bombards, continually batters the city's massive land walls, which the defenders are finally unable to block off.

Gunpowder thus becomes recognized as a decisive weapon.

During the siege, the opposing views on the Ottoman side are voiced in two war councils convened at critical moments.

Zaganos vehemently rejects the proposal to raise the siege.

He is given the task of preparing the last great assault.

The commander in chief, Mehmed II himself, on the day of the attack personally directs the operations against the breach opened in the city wall by his cannon.

On May 29, some of his soldiers force their way in.

Giustiniani is mortally wounded.

The emperor Constantine is last seen fighting on foot at one of the gates.

The day after the capture of the city, Candarli is arrested and soon afterwards is executed in Edirne.

He is replaced by Zaganos, who has become Mehmed's father-in-law.

Mehmed had had to consent to a three-day sack of the city, but, before the evening of the first day after its capture, he countermands his order.

Entering the city at the head of a procession, he goes straight to Hagia Sophia and converts it into a mosque, adding four minarets at the perimeter of the structure.

Afterward, he establishes charitable foundations and provides fourteen thousand gold ducats per annum for the upkeep and service of the mosque.

The Turks also convert Saint Savior in the Chora to a mosque, calling it Kariye Djami, and whitewash (and thus protect, perhaps inadvertently) its magnificent mosaics and frescoes.

The eighty thousand-man Turkish army encircling Constantinople, led personally by Mehmed II, inaugurates a siege of the city on April 6, 1453.

Emperor Constantine XI commands an army of only ten thousand men, left as the city’s sole defenders after the Turkish navy drives off an assisting Venetian naval fleet and erects a blockade.

Mehmed uses his fifty-six giant, stone-ball-firing cannons and twelve bombards, all Hungarian-made, to reduce the city’s massive walls, which the imperial forces are finally unable to block off.

The largest of their cannon is the Great Turkish Bombard, which requires an operating crew of two hundred men and seventy oxen, and ten thousand men to transport it.

Gunpowder makes the formerly devastating Greek fire obsolete, and becomes recognized as a decisive weapon.

Many war galleys now mount a large, fixed cannon that fires over the bow.

Such centerline bow guns, often flanked by several smaller guns, will soon become universal.

After a fifty-five-day bombardment, Mehmed enters the city on May 29, 1453; the forty-nine-year-old emperor bravely battles the Turks at one of the city’s gates until he is overwhelmed and killed by the attackers.

Mehmed permits his soldiers three days to plunder the defeated city, after which …