Islam came about in the 9th and 10th centuries, during and after the prophet mohammed's life.. it's a fairly "new" religion. Judaism predates it by about 1500 years, christianity about 700-1000. All of them are offshoots, or newer versions of the old Abrahamic religion.. ie, that's why all 3 are the "people of the book". That's why mohammed is the "last prophet".
Ancient Persians, taking on the Spartans, were not Islamic. Islam didn't start to spread out of Arabia till the 800-1000's and the battle with the spartans started a good 2000 years before it ever came around.. the crusades started about 1000-1200.