Although inhabited since the 1st century, the city of Zarqa grew significantly when immigrants from the Caspian Sea region arrived. The first settlement in the city was established in 1902 by Chechen immigrants who were displaced from the wars between the Ottoman and Russian Empires. They settled along the Zarqa River. At that time a station on the Hejaz Railway was built in the new settlement. The railway station turned Zarqa into an important hub. On 10 April 1905, the Ottoman governor issued a decree that allowed the Chechen immigrants to own lands which they settled on. The population then quickly grew in size. On 18 November 1928, the new Jordanian government issued a decree to establish the first municipal council for Zarqa.
After the Transjordan Frontier Force was formed in 1926, military bases were constructed in the city by the British Army and the city later became known as the “military city”. The headquarters of Jordan’s Arab Legion was in Zarqa. Today Zarqa has a population of over 600 thousand.