Regnvm Italiae et Gothorvm
Ostrogoths

Relations with the Empire
Theodoric's relations with his nominal suzerain, the Eastern Roman Emperor, were always strained, for political as well as for religious reasons. Especially during the reign of Anastasius, these led to several collisions, none of which however escalated into general warfare. In 504-505, Theodoric's forces launched a campaign to recover Pannonia and the strategically important town of Sirmium, formerly parts of the praetorian prefecture of Italy, which were now occupied by the Gepids. The campaign was successful, but it also led to a brief conflict with imperial troops, where the Goths and their allies were victorious. Domestically, the Acacian schism between the patriarchates of Rome and Constantinople, caused by imperial support for the Henotikon, as well as Anastasius' Monophysite beliefs, played into Theodoric's hands, since the clergy and the Roman aristocracy of Italy, headed by Pope Symmachus, vigorously opposed them. Thus, for a time, Theodoric could count on their support. The war between the Franks and Visigoths led to renewed friction between Theodoric and the Emperor, as Clovis successfully portrayed himself as the champion of the Catholic Church against the "heretical" Arian Goths, gaining the Emperor's support. This even led to the dispatch of a fleet by Anastasius in 508, which ravaged the coasts of Apulia.

With the ascension of Justin I in 518, a more harmonious relationship seemed to be restored. Eutharic, Theodoric's son-in-law and designated successor, was appointed consul for the year 519, while in 522, to celebrate the healing of the Acacian schism, Justin allowed both consuls to be appointed by Theodoric. Soon, however, renewed tension would result from Justin's anti-Arian legislation, and tensions grew between the Goths and the Senate, whose members, as Chalcedonians, now shifted their support to the Emperor. The suspicions of Theodoric were confirmed by the interception of compromising letters between leading senators and Constantinople, which led to the imprisonment and execution of Boethius in 524. Pope John I was sent to Constantinople to mediate on the Arians' behalf, and, although he achieved his mission, on his return he was imprisoned and died shortly after. These events further stirred popular sentiment against the Goths.
Death of Theodoric and dynastic disputes

After the death of Theodoric on 30 August 526, his achievements began to collapse. Since Eutharic had died in 523, Theodoric was succeeded by his infant grandson Athalaric, supervised by his mother, Amalasuntha, as regent. The lack of a strong heir caused the network of alliances that surrounded the Ostrogothic state to disintegrate: the Visigothic kingdom regained its autonomy under Amalaric, the relations with the Vandals turned increasingly hostile, and the Franks embarked again on expansion, subduing the Thuringians and the Burgundians and almost evicting the Visigoths from their last holdings in southern Gaul. The position of predominance which the Ostrogothic Kingdom had enjoyed under Theodoric in the West now passed irrevocably to the Franks.
This dangerous external climate was exacerbated by the regency's weak domestic position. Amalasuntha was Roman-educated and intended to continue her father's policies of conciliation between Goths and Romans. To that end, she actively courted the support of the Senate and the newly ascended Emperor Justinian I, even providing him with bases in Sicily during the Vandalic War. However, these ideas did not find much favour with the Gothic nobles, who in addition resented being ruled by a woman. They protested when she resolved to give her son a Roman education, preferring that Athalaric be raised as a warrior.
So far the facts...

now to the army
also here we want give only general informations. The army had strong roman elements. It is also true that some local units of the Numeri still existed with their old roman shield patterns. When the eastern Roman empire took those cities those units got again a new name. Technical speaking the names were the same, however the names were translated in greek: Numerus became Bandus (Banner). But that's the future.
The most strongest part of the goths were the heavy mounted lancers and the core of the native gothic infantry.