The Sakas were originally nomadic tribes of Central Asia but about 165-160 B.C. they were driven out of their land by another powerful nomadic tribe, the Yeuh-chi. They in turn swooped down on the Bactrian and Parthian empire and conquered a large portion of them between 140 to 120 B.C. As more and more of the Sakas were coming, the earlier ones pressed forward and some of them crossed the Hindukush and the Suleiman ranges and settled in the North-West of India.
Some of them got employment under the Parthian rulers and rose to the rank of “Satraps” or “viceroys.” This title was so much liked by the Sakas that even when they became independent rulers they continued to be called “Satraps”.
Slowly and steadily they established many independent kingdoms in the North-West of India, the chief among them are the following:
1. The Northern Saka Kingdom of Taxila
In fact it is very difficult to distinguish between the later Parthians and the Saka Satraps. Perhaps the first Saka rule of India was Maus, who is also linked with the Parthian history. He made Taxila as his capital and ruled over Gandhara and the territories around it. Towards the end of the first century B.C. he was a powerful king who assumed the title of “the great king of kings.” Maus was followed by Azes I and Azes II who are said to have extended their sway over eastern Punjab. Beyond this nothing definite is known about them.
2. The Northern Sakas Kingdom of Mathura
It is not known as to who the founder of this Saka kingdom of Mathura was or who shifted his capital from North-West of India to this place. But the Saka Satrap of Mathura made a great progress.
3. The Western Sakas Kingdom of Nasik
Because of certain pressure from the Yueh-Chi and Kushan tribes, who followed the Sakas in India, some of the Saka chiefs moved towards south and extended their sway over a vast area including Malwa, Gujarat, Cutch, Kathiawar and Maharashtra. These Satraps who ruled over this western region are known as the Western Satraps or Western Sakas.
4. The Saka Kingdom of Ujjain (Western Satraps)
The most important Saka kingdom was that of Ujjain. The founder of this kingdom was Chastana who came to the throne in about 78 A.D. According to some historians it was he who was the originator of the famous Saka era which begins from 78 A.D. He made Ujjain as his capital and ruled for about thirty two years. There were about twenty successors of Chastana who ruled from Ujjain for many centuries (from 1st Century to 4th Century A.D.).
The most famous successor of Chastana was Rudradaman I who is supposed to have ruled from 120 to 150 A.D. He was a great conqueror whose military exploits are vividly described in the Junagadh Rock Inscription, He defeated the proud Yaudheyas and wrested from them a great portion of their empire including the Eastern Punjab. His most important military achievement was against the Andhras. He conquered back all those territories from the Andhras which were once lost during the life time of his grand-father, Chastana, when Gautamiputra Satakarni conquered them. The Andhra king whom he defeated was Sri Pulmavi. Later on the differences were, however, patched up when Rudradaman married his daughter with the Andhra king. Rudradaman thus ruled over a vast region which included such territories as Gujarat, Saurashtra, Kutch, the lower Indus Valley, North Konkan, and Maru (in Rajputana) and many other parts including Eastern Punjab.
Some of these territories were definitely under Gautamiputra Satakarni. So we can conclude that Rudradaman wrested many parts from the Satavahanas or the Andhras.
After his death or Rudradaman in about 140 A.D.) his seventeen successors tried to maintain their ancestral kingdom, but ultimately their state was annexed by the rising Guptas (Chandragupta II) in the fourth century A.D.