The Roman Catholic and Eastern Orthodox patriarchates split from one another in the East – West Schism of 1054 AD, and Protestantism came into existence during the Protestant Reformation of the 16th century, splitting from the Roman Catholic Church.

* 1965 – Pope Paul VI and Patriarch Athenagoras simultaneously revoke mutual excommunications that had been in place since 1054.

This event is known as the East – West Schism, and it is traditionally dated to the year 1054, although it was more of a gradual process than a sudden break.

* The East – West Schism, between the Eastern Orthodox Church and the Roman Catholic Church in 1054

* 1054 – A supernova is seen by Chinese, Arab, and possibly Amerindian observers near the star Zeta Tauri.

* 1054 – Siward, Earl of Northumbria invades Scotland and defeats Macbeth, King of Scotland somewhere north of the Firth of Forth.

* 1054 – Three Roman legates break relations between Western and Eastern Christian Churches through the act of placing an invalidly-issued Papal bull of Excommunication on the altar of Hagia Sophia during Saturday afternoon divine liturgy.

* 1999 – Pope John Paul II travels to Romania becoming the first pope to visit a predominantly Eastern Orthodox country since the Great Schism in 1054.

Certain transparent materials with a small concentration of neodymium ions can be used in lasers as gain media for infrared wavelengths ( 1054 – 1064 nm ), e. g. Nd: YAG ( yttrium aluminium garnet ), Nd: YLF ( yttrium lithium fluoride ), Nd: YVO < sub > 4 </ sub > ( yttrium orthovanadate ), and Nd: glass.

Other famous pieces include the Boecis, a 258-line-long poem written entirely in the Limousin dialect of Occitan between the year 1000 and 1030 and inspired by Boethius's Consolation of Philosophy ; the Waldensian La Nobla Leyczon ( dated 1100 ), la Cançó de Santa Fe ( ca 1054 – 1076 ), the Romance of Flamenca ( 13th c .), the Song of the Albigensian Crusade ( 1213 – 1219?

The reigns of Vladimir the Great ( 980 – 1015 ) and his son Yaroslav the Wise ( 1019 – 1054 ) constitute the Golden Age of Kiev, which saw the acceptance of Orthodox Christianity from Byzantium and the creation of the first East Slavic written legal code, the Russkaya Pravda.

During Wrocław's early history, its control changed hands between Bohemia ( until 992, then 1038 – 1054 ), the Kingdom of Poland ( 992 – 1038 and 1054 – 1202 ), and, after the fragmentation of the Kingdom of Poland, the Piast-ruled duchy of Silesia.

* 1054 – Russian legal code of the Russkaya Pravda is created during the reign of Yaroslav I the Wise.

* June 21 – Pope Leo IX ( d. 1054 )

* July 4 – The SN 1054 supernova is recorded by the Chinese, Arab and possibly Native Americans near the star ζ Tauri.

** Yaroslav the Wise ( no earlier than 983 ), Prince of Rostov ( 987 – 1010 ), Prince of Novgorod ( 1010 – 1034 ), Grand Prince of Kiev ( 1016 – 1018, 1019 – 1054 ).

In 1054 King Edward sent Ealdred to Germany to obtain Emperor Henry III's help in returning Edward the Exile, son of Edmund Ironside, to England.

Pope Leo IX ( in office 1049 to 1054 ) also had family ties to the dynasty, since his grandfather Hugo III was the brother of Adelheid, the grandmother of Henry III.

He had been taken as a young child to Hungary, and in 1054 Bishop Ealdred of Worcester visited the Holy Roman Emperor, Henry III to secure his return, probably with a view to becoming Edward's heir.

Soon after her birth on 9 April 1054, Judith was betrothed to Philip, eldest son and heir of King Henry I of France.

Between 1050 and 1054 Lambert II, Count of Lens fought alongside the Baldwins against Henry III finding that this alliance best protected his interests.

In late January, early February 1054, Count Geoffrey and King Henry together invaded Normandy and marched down the Seine toward Rouen.

Henry responded by devastating Flanders and ravaging Lille and Tournai ( 1054 ).

* 1054 BC Shamshi-Adad IV, son of Tiglath-Pileser I, usurps the Assyrian throne from his nephew, Eriba-Adad II.

Robert Curthose ( c. 1054 – 3 February 1134 ), sometimes numbered Robert II or Robert III, was the Duke of Normandy from 1087 until 1106 and an unsuccessful claimant to the throne of the Kingdom of England.

" To the former belong the mutual revocation in 1965 of the anathemas of 1054 ( see below Contemporary developments ), returning the relics of Sabbas the Sanctified ( a common saint ) to Mar Saba in the same year, and the first visit of a Pope to an Orthodox country in a millennium ( Pope John Paul II accepting the invitation of the Patriarch of the Romanian Orthodox Church, Teoctist, in 1999 ), among others.

Ramon Berenguer II the Towhead or Cap de estopes ( 1053 or 1054 – December 5, 1082 ) was Count of Barcelona from 1076 until his death.

* Robert Curthose or Robert II ( c. 1051 or 1054 – 1134 ), Duke of Normandy, son of William the Conqueror, the first Norman king of England

* 1040 – 1054: Lambert II, ( son of Lambert I )

* George II of Georgia ( c. 1054 – 1112 ), king of Georgia 1072-1089

Lambert II, Count of Leuven, ( d. 1054 ) founded a chapter in 1047 in honour of Saint Gudula.

Hughes II de Montfort participated in the Battle of Mortemer in 1054 and the Battle of Hastings.

Lambert II, Count of Lens ( died 1054 ) was a French nobleman.

George II (, Giorgi II ) ( c. 1054 – 1112 ), of the Bagrationi Dynasty, was a king of Georgia from 1072 to 1089.

This type of supernova does not typically create the spectacular nebula more typical of Type II supernovas, such as SN 1054 which created the Crab Nebula.

An English invasion in 1054, with Siward, Earl of Northumbria, in command, had as its goal the installation of one " Máel Coluim, son of the King of the Cumbrians ".

In 1054, the English king Edward the Confessor dispatched Earl Siward of Northumbria against the Scots, ruled by Mac Bethad mac Findláich ( Macbeth ), along with an otherwise unknown " Malcolm son of the king of the Cumbrians ", in Strathclyde.

It is far from certain that Eógan died at Carham, and it is reasonably certain that there were kings of Strathclyde as late as the 1054, when Edward the Confessor sent Earl Siward to install " Máel Coluim son of the king of the Cumbrians ".

On 15 September 1054, Ferdinand defeated his elder brother García at the Battle of Atapuerca and reduced Navarre to a vassal state under his late brother's young son, Sancho García IV.

García, the eldest legitimate son, was to be feudal overlord of his brothers, but he was soon challenged by his brothers, leading to the first partition of the kingdom after his death in the Battle of Atapuerca, in 1054.

Despite the death of his son Osbjorn, Siward defeated Mac Bethad in battle in 1054.