In 1094, the Greek Emperor Alexius I, Roman Emperor who ruled both the Western Roman Empire and Eastern Roman Empire of Greece, asked Pope Urban II for help. The Turkish army invaded the eastern province of the Greek Empire and was approaching Constantinople as the capital of the Roman Empire. The pope called on Western European knights to abandon divisions and petty conflicts to help the Greeks in the east. He called them together to participate in the Holy War to Jerusalem. The first Crusade will begin soon.