Since the Byzantines and Sassanian Persians considered each other the only real civilizations in the region, they fought each other numerous times in the early 600s C.E. over control of what is today East Turkey and Iraq. These were intense religious wars (Christian vs. Zoroastrian) and greatly weakened both empires at just the wrong time, leading to a very porous southern defense and miscalculation of the Islamic Armies. Because of this, the Muslims were able to completely destroy Sassanid Persia and conquer over two-thirds of the Byzantine Empire.
The expansion successively of Hittite, Assyrian, Babylonian and Persian, Macedonian and Roman Empires in the West, and Aryan and Indian empires in the East.
Pretty much every thing other than religion...
An empire is created by expansion. A political empire, such as the Persian, Roman, British, etc, was created by the addition of territory ruled by the homeland. There are other types of empires. For example, there is a publishing empire, in which one publisher owns a variety of newspapers, magazines, comic books, instruction manuals, and so forth. Expansion is the keyword in creating an empire.
To strengthen their rule, they disregarded the laws of Islam and did whatever they could to gain power (like killing children, babies, and innocent people).
Byzantine
The Byzantine and Persian empires were weak.
the empires and dynasties of China, Byzantine, and Abbasid were able to establish a strong trade network that led to the spread and emergence of religions that contributed to the expansion of religions and contact between existing empires
Revelation in the holy Quran and in their strong faith
Revelation in the holy Quran and in their strong faith
King Chandragupta took the territory into Indian control.
The expansion successively of Hittite, Assyrian, Babylonian and Persian, Macedonian and Roman Empires in the West, and Aryan and Indian empires in the East.
The first probes into Byzantine (eastern Roman) territory began immediately after the conclusion of the last war between the Byzantine and Sassanid Persian Empires. One of the earliest battles of note was the battle of Mut'a in 629 and the most significant afterwards was the battle of Yarmuck, between 635-636 AD when Byzantine forces were badly defeated.
Both empires shared similar laws and traditions.
The Byzantine Empire, as well as the Persian Empire were located near the Arabian Peninsula, in the budding years of Islam.
Trade routes/Renaissance
Alexander took over the Persian Empirein its entirety.
1st - Age of Empires 2nd - Age of Empires - The Rise of Rome - Expansion 3rd - Age of Empires II - The Age of Kings 4th - Age of Empires II - The Conquerors - Expansion 5th - Age of Empires III 6th - Age of Empires III - The Warchiefs - Expansion 7th - Age of Empires III - The Asian Dynasties - Expansion