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The Crusades of the 15th century are those Crusades that follow the Crusades after Acre, 1291–1399, throughout the next hundred years. In this time-period, the threat from the Ottoman Empire dominated the Christian world, but further threats—from the Mamluks, Moors, and heretics—impinged upon the Christian West as well. The Ottomans gained significant territory in all theaters, but did not defeat Hospitaller Rhodes, nor advance past the Balkans; in addition, the Reconquista was completed, and heresies continued to be suppressed.
The Fall of Constantinople in 1453 marked the end of the Byzantine Empire, and the Teutonic Knights were spent as a fighting force. The Crusades would continue for almost another 100 years, with the expansion of the Ottoman Empire into a major world power—a level of international influence that lasted into the 20th century.
The Christian West France and England At the beginning of the 15th century, Charles VI of France had been king for two decades and France and England were consumed by the continuing Hundred Years' War. Richard II of England would soon be replaced by Henry IV of England. Neither of the kings were in a position to support a crusade, but they would both host the Byzantine emperor Manuel II Palaiologos in his quest to gain help in his fight against the Ottoman Empire. Manuel first met Charles at Charenton-le-Pont on 3 June 1400, and then Henry from December 1400 to February 1401 at Eltham Palace, returning to France on his journey home. Manuel received monetary support but little else.Chisholm, Hugh, ed. (1911). Manuel II., Palaeologus. Encyclopædia Britannica. 17 (11th ed.). Cambridge University Press. pg. 609.
During a lull in the fighting with the English, France became embroiled in the Armagnac–Burgundian Civil War, which began in 1407 and would continue for decades. Henry IV would be succeeded by his son Henry V of England, who renewed the offensive against France. In 1415, Charles' army was crushed by the English at the Battle of Agincourt, which led to the signing of the Treaty of Troyes.Jules Viard (1911). "Hundred Years' War". In Chisholm, Hugh (ed.). Encyclopædia Britannica 13 (11th ed.). Cambridge University Press. pgs. 803–804.
Following Agincourt, Sigismund of Luxembourg made a visit to Henry in hopes of making peace between England and France. His goal was to persuade Henry to modify his demands against the French. Henry had him enrolled in the Order of the Garter and Sigismund, in turn, inducted Henry into the Order of the Dragon. Henry had intended to crusade for the order after uniting the English and French thrones, but he died before fulfilling his plans. Sigismund left England several months later, having signed the Treaty of Canterbury acknowledging English claims to France.Chisholm, Hugh, ed. (1911). Sigismund. Encyclopædia Britannica. 25 (11th ed.). Cambridge University Press. pgs. 66–67.
Charles VI also received the archbishop Jean of Sultānīya, who arrived in Paris on 15 June 1403 as an ambassador from the emperor Timur. Timur offered an offensive and defensive alliance with Charles, as well as the development of commercial relations. Charles was only able to send an answer and an envoy shortly before Timur's death in 1405.
Western Schism
The Western Schism had begun in 1378 and was still plaguing the papacy when Boniface IX was elected pope on 2 November 1389. During his tenure, the Avignon claimants, Clement VII and Benedict XIII, maintained the Roman Curia in Avignon, under the protection of the French monarchy.Nicholas Aloysius Weber (1912). "Robert of Geneva". In Herbermann, Charles (ed.). Catholic Encyclopedia. 13. New York: Robert Appleton Company.Johann Peter Kirsch (1910). "Pedro de Luna". In Herbermann, Charles (ed.). Catholic Encyclopedia. 9. New York: Robert Appleton Company. In 1398 and 1399, Boniface had appealed to Christian Europe in favor of Manuel II Palaeologus, threatened at Constantinople by the Ottoman sultan Bayezid I, but there was little enthusiasm for a new crusade at such a time. Manuel's subsequent visit to France and England achieved little.Thomas Oestreich (1907). "Pope Boniface IX". In Herbermann, Charles (ed.). Catholic Encyclopedia. 2. New York: Robert Appleton Company.
Boniface IX died on 1 October 1404 and was succeeded by Innocent VII, whose uneventful papacy ended on 6 November 1406.Michael Ott (1910). "Pope Innocent VII". In Herbermann, Charles (ed.). Catholic Encyclopedia. 8. New York: Robert Appleton Company. After the Papal Conclave of 1406, the new pope took the name Gregory XII.Michael Ott (1910). "Pope Gregory XII". In Herbermann, Charles (ed.). Catholic Encyclopedia. 7. New York: Robert Appleton Company. Gregory started negotiations with Benedict XXIII, suggesting that they both resign, so a new pope could be elected to reunite the Catholic Church. When these talks ended in stalemate in 1408, Charles VI of France declared that his kingdom was neutral to both papal contenders.Chisholm, Hugh, ed. (1911). Charles VI. (King of France) Encyclopædia Britannica. 5 (11th ed.). Cambridge University Press. pgs. 919–920.
Charles helped to organise the Council of Pisa in 1409. This council was supposed to arrange for both Gregory and Benedict to resign, so that a new universally recognised pope could be elected. To oppose this, Benedict convoked the Council of Perpignan in November 1408, with little success. Since both Benedict and Gregory refused to abdicate, the only achievement in Pisa was that a third candidate to the Holy See was put forward on 26 June 1409 and became known as Alexander V.John Bertram Peterson (1907). "Pope Alexander V". In Herbermann, Charles (ed.). Catholic Encyclopedia. 1. New York: Robert Appleton Company.
In 1411, the antipope John XXIII proclaimed his own crusade against Ladislaus of Naples, the protector of rival Gregory XII. In 1409, Louis II of Anjou had liberated Rome from Ladislaus' occupation, and he joined John XXIII's crusade, where he attacked Ladislaus and defeated him at the Battle of Roccasecca on 19 May 1411.Johann Peter Kirsch (1910). "John XXIII". In Herbermann, Charles (ed.). Catholic Encyclopedia. 8. New York: Robert Appleton Company.
Council of Constance
The Council of Constance was held from 1414 to 1418 in the Bishopric of Constance. The council ended the Western Schism by deposing or accepting the resignation of the remaining papal claimants and by electing a new pope. The council also condemned Jan Hus as a heretic and facilitated his execution by the civil authority.Joseph Wilhelm (1910). "Jan Hus". In Herbermann, Charles (ed.). Catholic Encyclopedia. 13. New York: Robert Appleton Company. It also ruled on issues of national sovereignty, the rights of pagans and just war.Thomas Joseph Shahan (1908). "Council of Constance". In Herbermann, Charles (ed.). Catholic Encyclopedia. 4. New York: Robert Appleton Company.
After deposing John XXIII in 1415, the council was divided by the conflicting claims of Gregory XII and Benedict XIII. A compromise candidate Martin V was elected pope, at the age of 48, at the council on St. Martin's Day, 11 November 1417.Michael Ott (1910). "Pope Martin V". In Herbermann, Charles (ed.). Catholic Encyclopedia. 9. New York: Robert Appleton Company.
Crusades of Martin V After a long stay in Florence, Martin was able to enter Rome in September 1420. He at once set to work establishing order and restoring dilapidated churches, palaces, bridges, and other public structures. For this reconstruction, he engaged some famous masters of the Tuscan school and helped instigate the Roman Renaissance.L. Duchesne, C. Hayes and J. Valois (1911). "Martin V". In Chisholm, Hugh (ed.). Encyclopædia Britannica 17 (11th ed.). Cambridge University Press. pg. 793.
On 1 March 1420, Martin V issued a papal bull inviting all Christians to unite in a crusade against the Lollards led by John Wycliffe, the Hussites, and other heretics. The crusades were, however, ultimately unsuccessful.František Lützow (1911). "Hussites". In Chisholm, Hugh (ed.). Encyclopædia Britannica 14 (11th ed.). Cambridge University Press. pgs. 7–9.
In addition, Martin declared a crusade against the Ottoman Empire in 1420 in response to the rising pressure from the Ottoman Turks. In 1419–1420, Martin had diplomatic contacts with the Byzantine emperor Manuel II, who was invoking his own council in Constantinople. On 12 July 1420, the pope conceded to attach an indulgence to anyone who would contribute to a crusade against the Turks, which would be led by Sigismund. Martin also authorized a crusade against Africa in 1418 in relation to the slave trade.
Waldensian Crusade
The Waldensians (or Valdois) were a Christian sect that began as an ascetic movement. They were declared heretics in 1215 and, in 1487, Innocent VIII issued a bull Id Nostri Cordis for their extermination. A crusade to fulfill the bull order was organized and a military offensive was launched in the territories of Charles I of Savoy. Charles eventually intervened to save his territories from further turmoil and promised the Vaudois peace, but not before the offensive had devastated the area and many of the Vaudois had fled. The crusade prompted John Milton to write his sonnet On the Late Massacre in Piedmont.Nicholas Aloysius Weber (1910). "Pope Innocent VIII". In Herbermann, Charles (ed.). Catholic Encyclopedia. 8. New York: Robert Appleton Company
Military Orders The military orders were dominant in the 15th century, providing forces to deal with both Muslim and heretical threats. These included the Knights Hospitaller, headquartered at Rhodes; the Teutonic Knights, operating from the Ordensstaat in Central Europe and the Baltic; the Order of the Dragon formed to fight the Ottomans; and the remnants of the Knights Templar in Iberia.
Knights Hospitaller Hospitaller Rhodes was the strongest Christian presence in the Mediterranean and would remain so for decades. Their stronghold of Smyrna in Anatolia had been under their control since the Smyrniote Crusade in 1344. It was lost with the Siege of Smyrna in 1402, conquered by the Timurids who had replaced the Ottomans' dominance during the Ottoman Interregnum.Phillips, Walter Alison (1911). "St John of Jerusalem, Knights of the Order of the Hospital of". In Encyclopædia Britannica. 24. (11th ed.). Cambridge University Press. pgs. 12–19.
Philibert de Naillac was Grand Master from 1396 until his death in 1421, and the Order's military strength provided stability in the region, despite the presence of Barbary pirates, also known as the Ottoman corsairs.David McDowall Hannay (1911). "Barbary Pirates". In Chisholm, Hugh (ed.). Encyclopædia Britannica 3 (11th ed.). Cambridge University Press. pgs. 383–384. The position of the Order as a Mediterranean seapower was strengthened by commercial treaties with Venice, Pisa, Genoa, and Egypt.
Confronted by the now firmly established Ottomans, the Hospitallers needed another stronghold on the mainland to support their headquarters at Rhodes. De Naillac identified a suitable site across from the island of Kos, then controlled by the Genoese. Bodrum Castle, known as the Castle of Saint Peter, was built by the Order in the site of a fortification occupied as early as 1110 BC as well as of a Turkish castle in the 11th century. Construction began in 1404 and workers were guaranteed a reservation in heaven by a papal decree in 1409. They used material from the nearby Mausoleum of Halicarnassus to fortify the castle. The inner structures were finished in 1406 and the first walls were not completed until 1437.Artemi, Eirini (2011). Diasporic Communities in Rhodes, 1350–1450. Ecclesiastical Lighthouse, vol., 237-247.