Second Imperial Civil War (Premysloides Dynasty)

Background
Enthronment of Romanos V, stabilization of his realm and various conflicts put shadow on obscure succession issue. While John Angelos was executed by Hungarian King Andrew and his son sent to Empire as hostage, his younger brother Manuel was still alive and from John death, Manuel rallying mercenaries, volunteers, dissatisfied elements and very few remaining loyalists of his father and was, despite his age (75 years old), enable to gather army. However, he decided to put forward his son, grandson of Isaac II Angelos, Andreas Angelos, as claimant of throne.

Manuel Army was financed by Saint Atlantis supporters, anti-Imperial forces of First Pan-European War and by various aristocrats and nobles, he collected about 600,000 gold coins from various supporters and allies from various countries and about 90,000 strong army of veterans and experienced warriors, soldiers and officers.

Early Stage
Imperial Intelligence gathered various informations about preparation of Succession War against Emperor Romanos, but underestimated military capabilities and resources of Manuel Army. Intelligence estimated Manuel have 50,000 troops and was not able to recognize presence of Hospitallers, Teutonic Order and Grand Commonwealth Corps, as well as strong anti-Romanos sentiment in Serbia and Beograd, where Serbian Governor was in secret contact with Manuel Angelos and decided to open Beograd and Serbia to Manuel Army in exchange for Serbia independency, or at least strong autonomy. Manuel, in that time Catholic Christian, agreed, but demanded permission for Latin Catholic Church to spread in Serbia and Serbian Governor (whos name was punished by damnatio memoriae) agreed. Province of Serbia, while loyal to Orthodox Christianity and protection of Orthodox Emperor, was very dissatisfied with various reforms and changes, include large-scale economic reforms, regulation of agriculture and liberalization of trade and early industrialization, as they were "proud Pannonian peasants" and imperial officials look down on these "primitive peasants" (in comparison to Bosnia, which undergone full-scale changes and supported Empire reforms).

However, first battle happened in Hungary. King Stephen II was enemy of Romanos Angelos and he never wanted to respect peace with Romanos, in spite of his father Andrew. He met with Manuel and his allies, but their cooperation was crippled when one of Catholic Bishop called Stephen Cuman wife "Pagan prostitute... suitable for muslim harem, not for christian ruler," despite all later efforts of Manuel, Stephen and his son were enraged and pledge vengeance for this offence. However, they failed and in Battle of Vas, Hungarian Army was totally defeated and destroyed by Manuel Army, especially because of tactic and strategic mistakes and because of Cuman cavalry ferocity. King Stephen, Crown Prince Ladislau and his younger brother, Duke Andrew, fell in Battle and it initiated Hungarian Civil War which ruined most of Hungaria. Manuel forces had only small casualties, mostly among levied infantry.

Battle of Beograd
First clash between Manuel and Romanos forces occured in Beograd and it was terrible defeat of Romanos forces, as city was besieged and in middle of siege, Serbian Governor opened gates and also ignited rebellion among defenders against loyalists and imperial garrison. About 4,000 imperial troops were killed or captured and city conquered with minimal casualties on attacker side. Serbian Governor was appointed as "Serbian Grand Duke", but he was in fact only puppet of Manuel Angelos. This battle also proved weakness of imperial military fortification system, as fortress garrison were not able to help Beograd in time and Manuel Army passed around fortress in his campaign against Romanos forces. After fall of Beograd, Balkan Military Governor Marianos was tortured and executed.

Invasion of Bosnia
Bosnia Campaign was very short, as Bosnia is mountainous territory with few roads and full of very angry and very loyal citizens of Empire armed and trained in to guerilla fight under command of Radana Argyros. Aside of few clashes, invasion was stopped and Manuel Army moved to south, to Macedonia and Kosovo. Only real battle of Bosnia invasion was siege of merchant city Vukovar, but this siege was draw, as Manuel Army plundered city, but was not able to conquer Imperial Citadel and capture whole county.