The Byzantine-Seljuk Wars were a series of decisive battles that shifted the balance of power in Asia Minor and Syria from the Byzantine Empire to the Seljuk Turks. Riding from the steppes of Central Asia, the Seljuk Turks replicated tactics practiced by the Huns hundreds of years earlier against a similar Roman opponent but now combining it with new-found Islamic zeal; in many ways, the Seljuk Turks resumed the conquests of the Muslims in the Byzantine-Arab Wars initiated by the Rashidun, Umayyad and Abbasid Caliphate in the Levant, North Africa and Asia Minor. Today, the Battle of Manzikert is widely seen as the moment when the Byzantines lost the war against the Turks; however the Byzantine military was of questionable quality before 1071 with regular Turkish incursions overrunning the failing theme system. Even after Manzikert, Byzantine rule over Asia Minor did not end immediately, nor were any heavy concessions levied by the Turks on their opponents — it took another 20 years before the Turks were in control of the entire Anatolian peninsula and not for long either. During the course of the war, the Seljuk Turks and their allies attacked the Fatimid Caliphate of Egypt, capturing Jerusalem and catalyzing the call for the First Crusade. Crusader assistance to Byzantium was mixed with treachery and looting, although substantial gains were made in the First Crusade. Within a hundred years of Manzikert, the Byzantines had (with Crusader assistance) successfully driven back the Turks from the coasts of Asia Minor and extended their influence right down to Palestine and even Egypt. Later, the Byzantines were unable to extract any more assistance, and the Fourth Crusade even led to the sack of Constantinople. Before the conflict petered out, the Seljuks managed to take more territory from the weakened Empire of Nicaea until the Sultanate itself was taken over by the Mongols, leading to the rise of the ghazis and the conclusive Byzantine-Ottoman wars.