955 -- How the West Got its Emperor Back

895 AD, circa (67 years Before the Ottonian Era)-- Beginning of the Terror of the Magyars, a nomadic people from the Steppe, who arrive on horseback from the East and establish themselves on the upper Danube.

The Magyars (Hungarians) were a Uralic-speaking pagan horse people from the Steppe, invade the Carpathian basin in central Europe. They begin launching raids across all of Europe, including into Germany, Italy, the Balkans, and even into Muslim Spain. This is time of great chaos in Europe.

Hungarian (Magyar) incursions into Western Europe and the Eastern Empire from the Carpathian Basin during the 10th Century, when they were the terror of Europe.

907 -- Magyars Conquer the Hungarian Plain. The Battle of Pressburg. (55 BOE) . The Hungarians annihilate a Bavarian Army near present-day Bratislava, establishing their control over the Carpathian basin.

This battle is considered one of the most significant battles in the history of Hungary and marks the conclusion of the Hungarian conquest. The most significant result of the Battle of Pressburg is that the Hungarians secured the lands they gained during the Hungarian conquest of the Carpathian Basin. This prevented a German re-invasion and established the Kingdom of Hungary. (WP)

936 -- (26 BOE)  Otto (Otto I, Otto the Great) crowned King of Germany, at Aachen. by virtue of inheriting the title of Duke of the Saxons.

937 -- Otto of Germany puts down rebellion of various German dukes against his rule as King of Germany.

955 -- (7 BOE) The End of the Magyar Terror. Battle of Lechfeld. Decisive defeat of the Magyars by Otto I of Germany near present-day Augsburg, Bavaria.  This decisive victory puts to an end a long period of instability in central Europe from invasions and raids of the Magyar cavalry, confining them to the Hungarian Plain and surrounding areas.

According to Widukind, Otto had at his disposal eight legiones included three from Bavaria, two from Swabia, one from Franconia under Duke Conrad and one well-trained legion from Bohemia, The eighth division, commanded by Otto, and slightly larger than the others, included Saxons, Thuringians, and the King's personal guard, the legio regia. Otto's army may have numbered 7,000–9,000 troops. Augusburg was defended by professional milites soldiers.

955 -- Last of the Signficant Popes from the Papal Dark Ages.  John XII selected Pope.

He was related to the counts of Tusculum, a powerful Roman family which had dominated papal politics for over half a century. He became pope in his late teenage years or early twenties. John XII's pontificate became infamous for the alleged depravity and worldliness with which he conducted his office. 

960 -- (2 BOE) Pope John XII leads a Papal army against the Germanic Lombards, who had conquered Papal territories in Italy.

John personally led an attack against the Lombard duchies of Beneventum and Capua, presumably to reclaim parts of the Papal States which had been lost to them. Confronted by the sight of John marching at the head of an army of men from Tusculum and Spoleto, the dukes of Beneventum and Capua appealed for help from Gisulf I of Salerno, who came to their aid.John retreated north and entered into negotiations with Gisulf at Terracina. A treaty was secured between the two parties, and the price for Gisulf's non-interference was John agreeing that the papacy would no longer claim Salerno as a Papal patrimony

961 -- Otto invades Italy in support of Pope John XII. He is successful against the Lombards menancing the Papal lands. He takes the title King of Italy.

In 960, Pope John XII clashed with the Germanic-speaking Lombards to the south. Unable to control Rome easily, he sought help from King Otto I of Germany and crowned him emperor. 

962 Feb 2 (1 OE) -- Otto I, Duke of Saxony, King of Germany and King of Italy, is crowned Western Roman Emperor in Rome by Pope John XII. Otto the Great is perhaps the first meaningful western emperor of the medieval era. A condition of being emperor was the obligation to the protect the integrity of the Papal lands around Rome. From Otto forward, the line of Emperor sof the West, being Germany-based in their home realms, could project power on both sides of the Alps. This was something the old Roman Empire had never been able to do successful. It was a stability that required the Germanization (Gothification) of the western Empire, which had largely happened by the year 700.

John soon fell out with Otto, leading to an attempt by Otto to depose him. (WP)

964 -- (3 OE) Death of Pope John XII . He is succeeded by Benedict V, who is soon overthrown by Otto and who dies in exile in Augsburg. This is followed by the short papacy of Leo VIII. End of the period of Papal history known as the Saeculum obscurum, the Papal Dark Ages.

(Latin: the Dark Age) was a period in the history of the Papacy beginning roughly with the installation of Pope Sergius III in 904 and lasting for sixty years until the death of Pope John XII in 964. During this period, the popes were supposedly influenced strongly by a powerful and allegedly corrupt aristocratic family, the Theophylacti, and their relatives.

Theophylact's wife Theodora and daughter Marozia held a great influence over the papal selection and religious affairs in Rome through conspiracies, affairs, and marriages.

Marozia became the concubine of Pope Sergius III when she was 15 and later took other lovers and husbands. She ensured that her son John was seated as Pope John XI according to Antapodosis sive Res per Europam gestae (958–962), by Liutprand of Cremona (c. 920–972). Liutprand affirms that Marozia arranged the murder of her former lover Pope John X (who had originally been nominated for office by Theodora) through her then husband Guy of Tuscany possibly to secure the elevation of her current favourite as Pope Leo VI.

965 Oct 1 -- Papacy of John XIII, who reigns as Pope for seven years. From John XIII forward the line of Popes becomes much more significant in regard to the definition of imperial power in the west.

After John XIII's restoration, he worked with the Emperor on ecclesiastical improvements. It was decided in a council held at Rome in the beginning of 967 in the emperor's presence that Grado was to be the patriarchal and metropolitan church of the whole of the Veneto. At another council at Ravenna in April 967, Otto again “restored to the apostolic Pope John the city and territory of Ravenna and many other possessions which had for some time been lost to the Popes.” At around this time he also created, at Otto's request, the Archbishopric of Magdeburg.

967 -- Otto I has his son his son Otto II crowned as co-emperor by John XIII in Rome.

Depiction of Emperor Otto I on his seal in 968. (source)