As the head of the Fourth International, Trotsky continued in exile in Mexico to oppose the Stalinist bureaucracy in the Soviet Union.

** July 17 – The armies of the Fourth Crusade capture Constantinople by assault ; the Byzantine emperor Alexius III flees from his capital into exile.

In the 1970s they issued a report titled " Security and the Fourth International " which alleged, amongst other things, that leading SWP member Joseph Hansen, who had been an assistant to Leon Trotsky during his Mexico City exile, was an accomplice in his assassination alleging that he and, by implication the SWP, were agents of the Soviet secret police ( GPU ).

He was eventually convinced to come out of exile and journey to the mother-ship of the Fourth Host of the Celestials to assist the Eternals in battle against the Deviants by the Eternal called Sprite.

The Latins, who had conquered the city of Constantinople in 1204 during the Fourth Crusade, established a Latin Empire ( 1204 – 61 ), divided the former Byzantine territories in the Balkans and the Aegean among themselves, and forced the Byzantine Emperors into exile at Nicaea ( present-day Iznik ).

Following this ruling, Alford petitioned for a writ of habeas corpus in the United States District Court for the Middle District of North Carolina, which upheld the initial ruling, and subsequently to the United States Court of Appeals for the Fourth Circuit which ruled that Alford's plea was not voluntary, because it was made under fear of the death penalty.

In 1215, the bishops of the Catholic Church met at the Fourth Council of the Lateran under Pope Innocent III.

" The Fourth Council of the Lateran in 1215 had spoken of " Jesus Christ, whose body and blood are truly contained in the sacrament of the altar under the forms of bread and wine ; the bread being changed ( transsubstantiatis ) by divine power into the body, and the wine into the blood.

The Fourth Republic comprised under a parliamentary form of government controlled by a series of coalitions.

While Elagabalus was still on his way to Rome, brief revolts broke out by the Fourth Legion at the instigation of Gellius Maximus, and the Third Legion, which itself had been responsible for the elevation of Elagabalus to the throne, under the command of Senator Verus.

In the course of the war of the Fourth Coalition against Napoleon, troops under Bernadotte occupied the neutral Lübeck after a battle against Blücher on November 6, 1806.

The Fourth Thai-Lao Friendship Bridge is under construction and is hoped to be completed by December 2012 linking Kunming to Bokeo, Laos and Chiang Rai.

* 1799 – Fourth Anglo-Mysore War: The Battle of Seringapatam: The siege of Seringapatam ends when the city is invaded and Tipu Sultan killed by the besieging British army, under the command of General George Harris.

CPC agreed to form the New Fourth Army and the 8th Route Army which were nominally under the command of the National Revolutionary Army.

At a federal level, racial profiling is challenged by both the Fourth Amendment of the U. S. Constitution which guarantees the right to be safe from search and seizure without a warrant ( which is to be issued " upon probable cause "), and the Fourteenth Amendment which requires that all citizens be treated equally under the law.

The Fourth Council of the Lateran, which convened beginning November 11, 1215, spoke of the bread and wine as " transubstantiated " into the body and blood of Christ: " His body and blood are truly contained in the sacrament of the altar under the forms of bread and wine, the bread and wine having been transubstantiated, by God's power, into his body and blood ".

The Supreme Court ruled that some searches and seizures may violate the reasonableness requirement under the Fourth Amendment, even if a warrant is supported by probable cause and is limited in scope.

If a person remains free to disregard questioning by the government, there has been no intrusion upon the person's liberty or privacy under the Fourth Amendment — there has been no seizure.

A search incidental to an arrest that is not permissible under state law does not violate the Fourth Amendment, if the arresting officer has probable cause.

Courts have treated this area as an extension of the house and as such subject to all the privacy protections afforded a person ’ s home ( unlike a person's open fields ) under the Fourth Amendment.

Court cases challenged the enforcement of the 18th Amendment as violations of rights guaranteed under the Fourth and Fifth Amendments.

The Fourth Council of the Lateran, held under Pope Innocent III, decreed ( canon xv ): " We interdict hunting or hawking to all clerics ".

Article 49 of Fourth Geneva Convention ( adopted in 1949 and now part of customary international law ) prohibits mass movement of people out of or into of occupied territory under belligerent military occupation:

* Fourth Military District: Arkansas and Mississippi, under General Edward Ord

In a broader view, the Long March included two other forces retreating under pressure from the Kuomintang: the Second Red Army and the Fourth Red Army.

When the Fourth Red Army under Zhang Guotao was formed in the Sichuan-Shaanxi border area from several smaller units, no standard nomenclature of the armies of the Communist Party existed ; moreover, during the Chinese Civil War central control of separate Communist-controlled enclaves within China was limited.

In June – July 1935, the troops under Mao united with the Fourth Red Army, led by Zhang Guotao, which had retreated west from Henan.

A Fourth Corps, under Lt. Gen. Richard H. Anderson, was organized on October 19, 1864 ; on April 8, 1865, it was merged into the Second Corps.

In New York City, on April 30, 1951, the Board of Directors of the Knights of Columbus adopted a resolution to amend the text of their Pledge of Allegiance at the opening of each of the meetings of the 800 Fourth Degree Assemblies of the Knights of Columbus by addition of the words " under God " after the words " one nation.

* 1203 – Isaac II Angelos, restored Eastern Roman Emperor, declares his son Alexios IV Angelos co-emperor after pressure from the forces of the Fourth Crusade.

Alexios V Doukas, surnamed Mourtzouphlos (, d. December 1205, Constantinople ) was Byzantine Emperor ( 5 February – 12 April 1204 ) during the second and final siege of Constantinople by the participants of the Fourth Crusade.

* 1807 – Emperor Napoleon's French Grande Armée defeats the Russian Army at the Battle of Friedland in Poland ( modern Russian Kaliningrad Oblast ) ending the War of the Fourth Coalition.

At the insistence of Charles, Martin IV excommunicated the Roman Emperor Michael VIII Palaeologus, who stood in the way of Charles's plans to restore the Latin Empire of the East that had been established in the aftermath of the Fourth Crusade.

* The Constantinople suburb of Beyoğlu ( then known as Pera ) is given to the Republic of Genoa by the Byzantine Emperor Michael VIII Palaeologus, in return for Genoa's support of the Empire after the Fourth Crusade and the sacking of Constantinople.

** August 1 – The Fourth Crusade elevates Alexius IV as Byzantine Emperor, after the citizens of Constantinople proclaim as emperor Isaac II Angelus ( Alexius IV's father ).

** Fourth son: Imperial Prince Kanenari ( 懐成親王 ) ( Emperor Emperor Chūkyō )

** Fourth son: Imperial Prince Hisahito ( 久仁親王 ) ( Emperor Go-Fukakusa )

In 1204, the city was bought by the Republic of Venice as part of a complicated political deal which involved among other things, the Crusaders of the Fourth Crusade restoring the deposed Eastern Roman Emperor Isaac II Angelus to his throne.

In the aftermath of the Fourth Crusade, with a Latin Emperor under the influence of the Venetians established at Constantinople, the Venetian Marco Sanudo conquered the island and soon captured the rest of the islands of the Cyclades, establishing himself as Duke of Naxia, or Duke of the Archipelago.

** Fourth son: Imperial Prince Tomihito ( 富仁親王 ) ( Emperor Hanazono )

** Fourth son: Imperial Prince Asahito ( 朝仁親王 ), also known as Tomohito ( Emperor Higashiyama )

** Fourth son: Imperial Prince Takahira ( 尊成親王 ) – later Emperor Go-Toba

Claudius, Fourth Roman Emperor

# Fourth son: Yichu ( 1831 – 1861 ), future Xianfeng Emperor, son of Empress Xiaoquancheng

Early in the fifth century AD Claudian, in his poem, On the Fourth Consulship of the Emperor Honorius, Book VIII, rhapsodizes on the conquests of the emperor Theodosius I, declaring that the Orcades ran red with Saxon slaughter ; Thule was warm with the blood of Picts ; ice-bound Hibernia wept for the heaps of slain Scots.

Besides other honors, Emperor Go-Daigo had given Takauji the title of Chinjufu-shogun, or Commander-in-chief of the Defense of the North, and the courtly title of the Fourth Rank, Junior Grade.

The Fourth Crusade was also sealed between Holy Roman Emperor Frederick II and the Sultan of Babylon in 1229 with a gift of a White Cockatoo.

* Fourth wife ( 1816 ) of Emperor Franz II.

* Fourth son of Emperor Leopold II and Empress Maria Ludovika.

* Fourth son of Emperor Franz II and Empress Maria Theresia.

The Senate's last known act was to elect Nicolaus Kanabus as Emperor in opposition against Isaac II and Alexius IV during the Fourth Crusade.

Three days after the junta removed the Emperor from his palace to imprisonment at the headquarters of the Fourth Division, this group appointed him their chairman and president of Ethiopia.