The Seljuq Turks' invasion of Asia Minor was detrimental to the Byzantine Empire because it significantly weakened its territorial control and military strength. The loss of key regions, including Anatolia, diminished the empire's resources and manpower, leading to economic decline. Additionally, the invasion disrupted trade routes and contributed to social unrest, ultimately paving the way for further incursions and the eventual fall of the Byzantine Empire.
Seljuq himself.
The Crusades showed the growing strength of midieval Europe by conquering the Levant of the much powerful Seljuq Empire. It also showed the growing strength as Europeans as they became more involved in the world as Venice controlling trade in the Levant, between Europe and Asia. Genoa grew as a long time power as it dominated trade in Western Mediterranean. A growth in economy in states in Spain such as Catile and Aragon ended Moorish Spain and showed their might with massacres of Muslims and Jews. The Crusades saw unity in their states as they could topple Byzantines, Prussians, Jews and Muslims. A growth in trade lead to an increase of power and money that allowed them to conquer Cyprus, Crete, Thessalonki and Mediterranean Islamic pirates of Adriatic Sea. It showed society and European countries fill the power hole of the waning Byzantine Empire.
The Seljuq dynasty was an Oghuz Turk Sunni Muslim dynasty that gradually became a Persianate society and contributed to the Turko-Persian tradition in the medieval West and Central Asia. Wikipedia
Great Seljuq Empire ended in 1194.
Great Seljuq Empire was created in 1037.
The underlying premise of the question is incorrect. The Byzantine Empire never converted to Islam and Islam was, by and large, illegal within the Byzantine Empire for as long as it existed. The reason why the territory formerly controlled by the Byzantine Empire became Muslim-majority was because it was conquered by various Islamic States such as the Rashidun Caliphate, the Umayyad Caliphate, the Seljuq Turkish Empire, and the Ottoman Empire (which finished the job).
Muhammad I - Seljuq sultan - died in 1118.
Seljuq campaigns in the Aegean happened in 1081.
Toghrul III of Seljuq died in 1194.
Pope Urban II granted help to the Byzantine emperor against the Seljuq Turks primarily to assist in repelling the Turkish advances that threatened Byzantine territory and Christian lands. Additionally, he aimed to unify the Western and Eastern Christian churches under his leadership, strengthening Christendom against a common enemy. This call for aid ultimately led to the launch of the First Crusade in 1096, as Urban sought to reclaim the Holy Land from Muslim control.
Mahmud II of Great Seljuq died in 1131.
Modern-day Turkey, modern-day Kyrgyzstan, the Middle East, and the Arabian Peninsula all composed the Great Seljuq Empire, which existed 1000 years ago.
shahs
Seljuq himself.
The original purpose of the Crusades was for soldiers and princes from western Europe to fight on the side of the Byzantine emperor against the Seljuq Sultanate of Rum. Later, West European princes set up small kingdoms in Jerusalem, Antioch, Tripoli, and Tyre.