Answer:
Holy War: a war declared or waged in support of a religious cause.
Islam: the religion of the Muslims, a monotheistic faith regarded as revealed through Muhammad as the Prophet of Allah.
Seljuk Turks: The Great Seljuk Empire or the Seljuk Empire was a high medieval Turko-Persian Sunni Muslim empire, originating from the Qiniq branch of Oghuz Turks.
Explanation:
It's that simple ;)
