good lord you are persistent. sense when does hiring mercenary mean you are bad at fighting? it was supper common everywhere basically until the thirty years war. also they seemed to held the Muslims back pretty well for centuries despite being outnumbered and having a succession of fairly bad rulers. the crusaders got stomped on constantly after their initial success.
let me give you the wiki quotes:
The Crusades were a series of intermittent Papal sanctioned military campaigns beginning in the late 11th-century. They commenced with a call to arms by Pope Urban II who was responding to a request for military support for the Byzantine Empire. The Byzantine Emperor, Alexios I, needed military reinforcements for the conflict with the westward migrating Turks in Anatolia. Historians debate Urban and the Crusader’s primary motivations. One of Urban's stated aims was to guarantee pilgrims access to the holy sites in the Holy Land that were under Muslim control while his wider strategy may have been to establish himself as head of the united Church and bringing together the Eastern and Western branches of Christendom that had been divided since their split in 1054. What is known though is the unprecedented response to Urban’s preaching and the basis it established for later crusades.
emperor asks for a bit of help. and that means the byzantine army is terrible?
To take the city by force, the crusaders first needed to cross the Bosphorus. About 200 ships, horse transports, and galleys delivered the crusading army across the narrow strait, where Alexios III had lined up the Byzantine army in battle formation along the shore, north of the suburb of Galata. The Crusader knights charged straight out of the horse transports, and the Byzantine army fled south. The Crusaders followed and attacked the Tower of Galata, which held the northern end of the massive chain that blocked access to the Golden Horn. As they laid siege to the Tower, the Byzantines counterattacked with some initial success. The crusaders rallied, and the Byzantines retreated to the Tower, but the crusaders were able to follow the soldiers through the Gate and took the Tower. The Golden Horn now lay open to the Crusaders, and the Venetian fleet entered. The Crusaders sailed alongside Constantinople with 10 galleys to display the would-be Alexios IV, but from the walls of the city citizens taunted the puzzled crusaders, who had been led to believe that they would rise up to welcome the young pretender Alexios as a liberator.[38]
On 11 July, the Crusaders took positions opposite the Palace of Blachernae on the northwest corner of the city. Their first attempts were repulsed, but on 17 July, with four divisions attacking the land walls while the Venetian fleet attacked the sea walls from the Golden Horn, the Venetians took a section of the wall of about 25 towers, while the Varangian guard held off the Crusaders on the land wall. The Varangians shifted to meet the new threat, and the Venetians retreated under the screen of fire. The fire destroyed about 120 acres (0.49 km2) of the city and left some 20,000 people homeless.[39]
Alexios III finally took offensive action, leading 17 divisions from the St. Romanus Gate, vastly outnumbering the crusaders. Alexios III's army of about 8,500 men faced the Crusaders' seven divisions (about 3,500 men), but his courage failed, and the Byzantine army returned to the city without a fight.[40] The unforced retreat and the effects of the fire greatly damaged morale, and the disgraced Alexios III abandoned his subjects, slipping out of the city and fleeing to Mosynopolis in Thrace.[41] The Imperial officials quickly deposed their runaway emperor and restored Isaac II, robbing the crusaders of the pretext for attack.[41] The crusaders were now in the quandary of having achieved their stated aim while being debarred from the actual objective, namely the reward that the younger Alexios had (unbeknownst to the Byzantines) promised them. The crusaders insisted that they would only recognize the authority of Isaac II if his son was raised to co-emperor, and on 1 August the latter was crowned as Alexios Angelos IV, co-emperor.[41]
seems like a case of bad leadership to me not military failing
also literally the first part of this.
https://en.wikipedia.org/wiki/Byzantine_armyFrom the seventh to the 12th centuries, the Byzantine army was among the most powerful and effective military forces in the world – neither Middle Ages Europe nor (following its early successes) the fracturing Caliphate could match the strategies and the efficiency of the Byzantine army.
and if you read some dates you will notice that they were briefly reliant on mercenaries a bit after the first crusade do to loses of manpower. then leadership perpetuated it for a bit after trying to reform to combat it until the crusaders made it permanent due to their general fucking up of everything.
After the collapse of the theme-system in the 11th century, the Byzantines grew increasingly reliant on professional Tagmata troops, including ever-increasing numbers of foreign mercenaries. The Komnenian emperors made great efforts to re-establish a native army, instituting the pronoia system of land grants in exchange for military service. Nevertheless, mercenaries remained a staple feature of late Byzantine armies since the loss of Asia Minor reduced the Empire's recruiting-ground, while the abuse of the pronoia grants led to a progressive feudalism in the Empire. The Komnenian successes were undone by the subsequent Angeloi dynasty, leading to the dissolution of the Empire at the hands of the Fourth Crusade in 1204.
they were only less advance after the siege essentially destroyed them and yet somehow after all that they hung on for more than two centuries. shit indeed.