John I Portuguese Joao known as John of Aviz \a-'vezh\ (b. April 11, 1357, Lisbon—d. Aug. 14, 1433, Lisbon) King of Portugal (1385— 1433) and founder of the Aviz dynasty. The illegitimate son of Pedro I, he was elected king in 1385 despite the rivalry of Castilian candidates. He fought off a Castilian invasion (1385) and preserved Portugal’s inde¬ pendence. He made an alliance with England (1386), but a joint invasion of Leon was unsuccessful. John signed a 10-year truce with Castile in 1389, but frontier warfare was intermittent until 1411. He and his sons (including the youngest, later Henry the Navigator) captured Ceuta in Morocco in 1415, thus beginning the era of Portuguese expansion.
John II French Jean known as John the Good (b. April 16, 1319, near Le Mans, France—d. April 8, 1364, London, Eng.) King of France (1350-64). At odds with England and Navarre, he tried to make peace with the Navarrese king Charles II, then had him imprisoned in 1356. Edward the Black Prince, son of Edward III of England, led an invasion of southern France, defeating and capturing John at the Battle of Poitiers (1356). John was forced to sign the treaties of Bretigny and Calais (1360), which fixed an extravagant ransom and surrendered most of southwest¬ ern France to the English. See also Hundred Years' War.
John II Comnenus \kam-'ne-nos\ (b. Sept. 13, 1087—d. April 8,1143) Byzantine emperor (1118—43). The son of Alexius I Comnenus, he made it his mission to reconquer Byzantine territory lost to the Arabs, Turks, and Crusaders. He cancelled Venetian trading privileges in the empire but was forced to restore them after the Venetians launched a fleet to retaliate against him. John allied himself with the German emperor against Roger II of Sicily (1130). He reconquered Cilicia (1137) and won homage from Antioch, but he failed to defeat the Syrian Turks.
John III Ducas Vatatzes Vdyu-kos-vo-'tat-sezV (b. c. 1193—d. Nov. 3, 1254, Nymphaion) Emperor of Nicaea (1222-54). He succeeded The¬ odore I Lascaris and defeated rivals for the imperial throne in 1223. Two years later he triumphed over Latin forces loyal to his rivals and gained control of Asia Minor. He allied with Ivan Asen II against Epirus (1230) and besieged Constantinople (1235), prompting Asen to go to war with him (1235-37). He acquired territory in Bulgaria (1241) and Epirus
Joffre, detail of a portrait by H. Jac- quier, 1915
H. ROGER-VIOLLET
© 2006 Encyclopaedia Britannica, Inc.
John III Sobieski ► John Maurice of Nassau I 991
(1242) and supported a cultural revival from his capital at Nicaea, pav¬ ing the way for the eventual reestablishment of the Byzantine Empire. Venerated by his people, he was canonized in the Eastern church.
John III Sobieski \sob-'ya-ske\ Polish Jan Sobieski (b. Aug. 17, 1629, Olesko, Pol.—d. June 17,
1696, Wilanow) Elective king of Poland (1674-96). Named com¬ mander in chief of the Polish army (1668), he distinguished himself by victories over the Cossacks and Turks. His reputation was so great that he was elected king in preference to the Habsburgs’ candidate. In 1683 he concluded a treaty with Emperor Leopold I against the Ottoman Turks.
When a Turkish army approached Vienna later that year, he rushed there with troops, took command of the entire relief force, and achieved a brilliant victory, briefly restoring the kingdom of Poland-Lithuania to greatness for the last time. He was unsuccessful in a Hungarian cam¬ paign (1683-91) to liberate Moldavia and Walachia from Ottoman rule.
Later rebellion within his own family, with nobles fighting each other rather than the Turks, led finally to Poland’s downfall in the 18th century.
John V Palaeologus \,pa-le-'a-l3-g3s\ (b. June 18, 1332,
Didymoteichon—d. Feb. 16, 1391, Constantinople) Byzantine emperor (1341-91). The son of Andronicus III Palaeologus, he inherited the throne at age nine; John VI Cantacuzenus served as his regent and coemperor (1347-54). After the Ottoman Turks gained control of Galliopoli and threatened Constantinople, John V appealed to the West for help, propos¬ ing to end the schism between the Byzantine and Latin churches. Impov¬ erished by war, he was detained as a debtor when he visited Venice (1369). In 1371 he was forced to recognize Turkish overlords, who later helped him to regain the throne (1379) after he was deposed by his son.
John VI Cantacuzenus \ l kan-t3-kyu- , ze-nos\ (b. c. 1292—d. June 15, 1383, Mistra, Byzantine Empire) Byzantine emperor (1347-54). As chief adviser (1328-41) to Andronicus III Paiaeologus, he directed both domes¬ tic and foreign policy. He fought to serve as regent for the young John V Palaeologus, triumphing over John’s mother, Anna of Savoy, only by enlisting Turkish aid. From 1347 he ruled as coemperor with John V, but in 1354 he crowned his own son coemperor. With Venetian aid, John V then forced him to abdicate, and Cantacuzenus retired to a monastery, where he wrote his memoirs.
John VIII Palaeologus \,pa-le-'a-l3-g9s\ (b. Dec. 17/18, 1392—d. Oct. 31, 1448, Constantinople) Byzantine emperor (1421-48). The son of Manuel II Palaeologus, he was crowned coemperor with his father in 1408 and took effective control of the empire in 1421. He became sole emperor after his father’s death in 1425. Of the diminished and fragmented empire, he ruled only Constantinople and the surrounding area. The city was besieged by the Ottoman Turks (1422), and, when Thessaloniki fell to Turkish forces (1430), John appealed to the West for help. He united the Byzantine and Latin churches (1439), but joint efforts against the Turks failed, and the Byzantines refused to submit to the pope. John died amid intrigues over succession.
John XXII orig. Jacques Duese (b. Cahors, France—d. Dec. 4,1334, Avignon) Second Avignon pope (1316-34). The successor to Clement V, he established the papal court at Avignon on a permanent basis (see Avi¬ gnon papacy). He condemned the Spiritual Franciscans’ interpretation of the poverty of Christ and his Apostles and upheld papal authority over imperial elections against the opposition of the emperor, Louis IV. When John excommunicated Louis, the emperor retaliated by declaring him deposed (1328) and sponsoring the election of an antipope. John’s views on the beatific vision provoked accusations of heresy (1331-32). He is remembered for centralizing church administration and adding to the body of canon law.
John XXIII orig. Angelo Giuseppe Roncalli (b. Nov. 25, 1881, Sotto il Monte, Italy—d. June 3, 1963, Rome; beatified Sept. 3, 2000; feast day October 11) Pope (1958-63). He studied theology in Rome, was
ordained a priest in 1904, and held a variety of church offices. In 1944 he was named papal nuncio to newly liberated France, where he success¬ fully revived sympathy for the Vati¬ can. Made a cardinal in 1953, he was elected pope after the death of Pius XII (1939-58). Because of his advanced age, he was expected to be little more than a caretaker in the office, but instead he became the major reform¬ ing pope of the century. Eager to lead the church into the modem era, he called the Second Vatican Council in 1962, inviting Eastern Orthodox and Protestant observers to join Catholic delegates. He also sought to repair relations with the Jews. The council went on to make major reforms in Catholic liturgy and administration, though John died before its conclusion. An energetic advocate of world peace, he was one of the most popular popes in history. In 2000 he was beatified by John Paul II (1978-2005).
John, Augustus (Edwin) (b. Jan. 4, 1878, Tenby, Pembrokeshire, Wales—d. Oct. 31, 1961, Fordingbridge, Hampshire, Eng.) Welsh painter, portraitist, muralist, and draftsman. By the age of 20 he had won a repu¬ tation for his brilliant drawing technique. A colourful personality, he roamed Britain, living with Roma and learning their customs and lan¬ guage; the painting Encampment on Dartmoor (1906) is based on these experiences. He is best known for his portraits of leading European per¬ sonalities, including those of James Joyce and George Bernard Shaw.