Isaac II Angelos - First Reign

First Reign

Isaac II Angelos strengthened his position as emperor with dynastic marriages in 1185 and 1186. His niece, Eudokia Angelina, was married to Stefan, son of Stefan Nemanja of Serbia. Isaac's sister, Theodora, was married to the Italian marquis Conrad of Montferrat. In January 1186 Isaac himself married Margaret of Hungary (renamed Maria), daughter of King Béla III. Hungary was one of the Empire's largest and most powerful neighbours, and Margaret also had the benefit of high aristocratic descent, being related to the royal families of Kiev, the Holy Roman Empire, Italy, Provence, and earlier Byzantine dynasties.

Isaac inaugurated his reign with a decisive victory over the Norman King of Sicily William II (the Battle of Demetritzes, 7 November 1185), who had invaded the Balkans with 80,000 men and 200 ships towards the end of Andronicus I's reign. Elsewhere his policy was less successful. In late 1185, he sent a fleet of 80 galleys to liberate his brother Alexius III from Acre, but it was destroyed by the Normans of Sicily. He then sent a fleet of 70 ships, but it failed in its attempt to recover Cyprus from the rebellious noble Isaac Comnenus, thanks to Norman interference.

The oppressiveness of his taxes, increased to pay his armies and finance his marriage, resulted in a Bulgarian uprising late in 1185. The rebellion led to the establishment of the Second Bulgarian Empire under the Asen dynasty. In 1187, Alexios Branas, the victor over the Normans, was sent against the Bulgarians but turned his arms against his master, and attempted to seize Constantinople, only to be defeated and slain by Isaac's brother-in-law Conrad of Montferrat. Also in 1187, an agreement was made with Venice, in which the Venetian Republic would provide 40–100 galleys at six months' notice in exchange for favorable trading concessions. As each Venetian galley was manned by 140 oarsmen, that means there were about 18,000 Venetians still in the Empire even after Manuel I's arrests.

The Emperor's attention was next demanded in the east, where several claimants to the throne successively rose and fell. In 1189 the Holy Roman Emperor Frederick I Barbarossa sought and obtained permission to lead his troops on the Third Crusade through the Byzantine Empire; but he had no sooner crossed the border than Isaac, who had meanwhile sought an alliance with Saladin, threw every impediment in his way. In retaliation, Barbarossa's army occupied the city of Philippopolis and defeated a Byzantine army of 3,000 men that attempted to recapture the city. Thus compelled by force of arms, Isaac II was forced to fulfill his engagements in 1190. By 1196, Isaac II had allowed the once powerful Byzantine navy to decline to only 30 galleys.

The next five years were disturbed by continued warfare with Bulgaria, against which Isaac led several expeditions in person. In spite of their promising start, these ventures had little effect, and on one occasion in 1190 Isaac barely escaped with his life. The Byzantines suffered yet another major defeat in the battle of Arcadiopolis in 1194. While preparing for yet another offensive against Bulgaria in 1195, Alexios Angelos, the Emperor's older brother, taking advantage of the latter's absence from camp on a hunting expedition, proclaimed himself emperor, and was readily recognised by the soldiers as Emperor Alexios III. Isaac was blinded and imprisoned in Constantinople.