His participation in the attempted usurpation of John Komnenos the Fat in 1200 had caused him to be imprisoned until the accession of Isaac II Angelos, who was restored to the throne after having been deposed and imprisoned by his brother Alexios III, and his son Alexios IV Angelos, who were placed on the throne by the intervention of the Fourth Crusade in July 1203.

* 1694 – John George IV, Elector of Saxony ( b. 1668 )

When Frederick IV of Habsburg sided with Antipope John XXIII at the Council of Constance, Emperor Sigismund placed him under the Imperial ban.

He thus broke allegiance with Philip and assembled a broad coalition including Emperor Otto IV, King John I of England, Duke Henry I of Brabant, Count William I of Holland, Duke Theobald I of Lorraine, and Duke Henry III of Limburg.

The campaign was designed by John, who was the fulcrum of the alliances ; his plan being to draw the French away from Paris southward against himself and keep him occupied, while the main army, under Emperor Otto IV, marched on Paris from the north.

** John IV ( 1341 – 1345 )

** John IV ( 1415 – 1427 )

Pius IV sent the decrees to Mary, Queen of Scots, with a letter dated June 13, 1564, requesting her to publish them in Scotland, but she dared not do it in the face of John Knox and the Reformation.

Meetings between Pope John Paul II and the Assyrian Patriarch Mar Dinkha IV led to a common Christological declaration on 11 November 1994 that " the humanity to which the Blessed Virgin Mary gave birth always was that of the Son of God himself ".

Beginning with John the Faster, the Bishop of Constantinople ( John IV, 582-595 ) adopted as a formal title for himself the by-then-customary honorific, Ecumenical Patriarch (" pre-eminent father for the civilized world ") over the strong objections of Rome: a title based on the political prestige of Constantinople and its economic and cultural centrality in the Empire.

Shakespeare's Henry IV plays and Henry V adapted and developed the material in an earlier play called the Famous Victories of Henry V, in which Sir John " Jockey " Oldcastle appears as a dissolute companion of the young Henry.

Heinz was the grandfather of H. J. Heinz II, great-grandfather of U. S. Senator H. John Heinz III of Pennsylvania in the United States and great-great grandfather of Henry John Heinz IV, Andre Thierstein Heinz and Christopher Drake Heinz.

A silver Indo-Portuguese coin featuring a standing figure facing right with flag struck for and minted in Goa during the reign of John IV of Portugal | John IV.

* 2001 – John Bigelow IV, American golfer

The context of this reference is the 36 AD defeat of Herod Antipas in his conflict with Aretas IV of Nabatea, which the Jews of the time attributed to misfortune brought about by Herod's unjust execution of John.

Josephus stated ( Antiquities 18. 5. 2 ) that the AD 36 defeat of Herod Antipas in the conflicts with Aretas IV of Nabatea was widely considered by the Jews of the time as misfortune brought about by Herod's unjust execution of John the Baptist.

By 1212 John had successfully concluded alliances with Renault of Dammartin, who controlled Boulogne, and Count Ferdinand of Flanders, as well as Otto IV, a contender for the crown of Holy Roman Emperor in Germany ; Otto was also John's nephew.

Henry IV, John of Gaunt's son, returned Kenilworth to royal ownership when he took the throne in 1399 and made extensive use of the castle.

Early in the 14th century, an unknown author built upon the continuation of Petrus Guillermi, adding the biographies of popes Martin IV ( d. 1285 ) through John XXII ( 1316 – 1334 ), with information taken from the " Chronicon Pontificum " of Bernardus Guidonis, stopping abruptly in 1328.

King Henry IV ( despite being John of Gaunt's son ) passed the De heretico comburendo in 1401, which did not specifically ban the Lollards, but prohibited translating or owning the Bible and authorised burning heretics at the stake.

* Afonso de Paiva and Pero da Covilhã travel overland from Lisbon in search of the Kingdom of Prester John ( Ethiopia ).

No Prester John was to be found in Asia, so European imagination moved him around the blurry frontiers of " India " until they found an appropriately powerful kingdom for him in Ethiopia.

Marco Polo had discussed Ethiopia as a magnificent Christian land and Orthodox Christians had a legend that the nation would one day rise up and invade Arabia, but they did not place Prester John there.

Francisco Álvares book, which included the testimony of Covilhã, the Verdadeira Informação das Terras do Preste João das Indias (" A True Relation of the Lands of Prester John of the Indies ") was the first direct account of Ethiopia, greatly increasing European knowledge at the time, as it was presented to the pope, published and quoted by Giovanni Battista Ramusio.

By the time the emperor Lebna Dengel and the Portuguese had established diplomatic contact with each other in 1520, Prester John was the name by which Europeans knew the Emperor of Ethiopia.

However, their admonitions did little to stop Europeans from calling the King of Ethiopia Prester John.

Ethiopia has been claimed for many years as the origin of the Prester John legend, but most modern experts believe that the legend was simply adapted to fit that nation in the same fashion that it had been projected upon Ong Khan and Central Asia during the 13th century.

* Funding of land expeditions by Afonso de Paiva and Pêro da Covilhã to India and Ethiopia in search of Prester John land.

In 1968 at the request of Emperor Haile Selassie of Ethiopia, a team of 60 British and Ethiopian servicemen and scientists made the first descent of the Blue Nile from Lake Tana to a point near the Sudan border led by the eminent explorer Captain ( now Colonel ) John Blashford-Snell.

Prior to his appointment to Ethiopia by John F. Kennedy, Korry was European editor for Look magazine and a United Press correspondent in post-World War II Europe.

As the representative of the head of state, Vanier hosted a list of official guests, including United States president John Kennedy and Jacqueline Kennedy ; the Emperor of Ethiopia, Haile Selassie ; David Ben-Gurion, Prime Minister of Israel ; the Shah of Iran ; and General Charles de Gaulle, President of France.

Francisco Álvares book, which included the testimony of Covilhã, the Verdadeira Informação das Terras do Preste João das Indias (" A True Relation of the Lands of Prester John of the Indies ") was the first direct account of Ethiopia, greatly increasing European knowledge at the time, as it was presented to the pope, published and quoted by Giovanni Battista Ramusio.

* John Robert Moore, " Rasselas and the Early Travelers to Ethiopia ", Modern Language Quarterly, 1954 15 ( 1 ), 36 – 41 ;

He finally arrived at Massawa in 1603, proceeded to Debarwa where he met the chief of the Portuguese in Ethiopia, John Gabriel on 11 May, and four days later had made his way to Fremona, the Jesuit base in Ethiopia.

* John Spencer ( historian ) ( 1907 – 2005 ), also representative to Ethiopia

Enticed by the tales of riches that could be obtained by attacking Muslim shipping, Pinto joined a reconnaissance mission to the Red Sea, with a brief stop in Ethiopia to deliver a message to the Portuguese soldiers who were guarding Eleni of Ethiopia, the mother of " Prester John " ( Emperor Dawit II of Ethiopia ) in a mountain fortress.

Hall in establishing a centre for primate studies, extending socio-ecological principles to primates, supervising doctoral projects and leading field research in Ethiopia on the Gelada Baboon and in Morocco on the Barbary Macaque, subsequently developed by Robin Dunbar and John Deag respectively.

Yohannes IV ( Ge ' ez ዮሐንስ ፬ኛ Yōḥānnis ዮሓንስ, Amharic Yōhānnis, also known by the English equivalent " John ", 11 July 1837 – 10 March 1889 ), born Lij Kassay Mercha Ge ' ez, was Emperor of Ethiopia from 1872 until his death.

His full title was " His Imperial Majesty John IV, Conquering Lion of the Tribe of Judah, King of Zion, King of Kings of Ethiopia and Elect of God " or in Ethiopian " Ge ' ez

However, as John Spencer points out, Ethiopia was able to rely on the principle of postliminium -- that is, once enemy occupation is terminated, a state may act as if its existence had survived without interruption.

* Cities of Ethiopia: Mekelle by John Graham ( Addis Tribune, 12 October 2001 )