Yavanas, as the Indian literature knew them, were the first of the invading people in the post-Mauryan period. After Alexander, a large part of his empire came under the rule of his generals. About 250 BC Diodotus, the Seleucid governor of Bactria, proclaimed his independence. Antiochus II, the Seleucid king then marched towards India, and defeated an obscure Indian king Subhagasena in the valley of the Kabul in 206 BC.
He hurried back to Mesopotamia after taking many elephants and booty from him. On his return, Euthydemus I (one of the successors of Diodotus) became the first sovereign came to the tfrrone, the Greek impact on India became pronounced. Greek expansion in India was definitely the work of Demetrius I.
He was remembered as late as the days of the medieval English poet Chaucer who called him coins bear legends in Greek and Prakrit written in Greek and Kharoshthi. He made Sakala his capital, which he named Euthydemia in memory of his father. His title aniketus (invincible) is etched on his coins. A city in Sauvira was named Dattamitri after him. At this time Eucratides rebelled in Bactria. Consequently, Demetrius I lost Bactria.
Eucratides advanced towards India and made Taxila his capital after conquering some part of the north-western region. His coins have been found in Bactria, Siestan, Kabul valley, Kapisa and Gandhar.
However, he could not cross Jhelum. Demetrius I, on the other hand, ruled eastern Punjab and Sind. Greek rule in India finally got divided into two parts: dynasties of Demetrius and Eucratides. It was Demetrius II who was able to establish Greek control over Punjab, whole of Sind and Cutch.
Strabo says that the Greeks trampled the Ganges and Palibothra (Pataliputra). Patanjali states that the Yavanas besieged Saketa and Madhyamika (Nagari near Chittor). Gargi Samhita mentions that the Greeks after reducing Saket, the Panchala region and Mathura, reached Pataliputra (Kusumadhwaja). But they returned soon thereafter because of internal problems. All these conquests were most probably directed by Demetrius II assisted by Apollodotus and Menander.
Amongst all the Indo-Greek kings Menander was the most illustrious. He ruled for a long time from his capital Sagala, and his coins represent him in all stages of his life, from youth to old age. His kingdom, at its peak, covered an area extending from Kabul to Mathura. He is famous in literature from Milindapanho (The Questions of Milind) in which he is represented as having held conversations with Buddhist philosopher
Another Indo-Greek king called Apollodotus, probably the same as Bhagadatta of the Mahabharata conquered Indus valley and Gujarat, and at its widest, his territory extended from Barygaza to Kapisa and Gandhara. At this time, Eucratides removed Apollodotus from Kapisa and restruck his coins.
Eucratides was assassinated by his son Heliocles, whose successors ruled the region from Pushkalavati (Charsada) to Takshashila till 25 BC, when the Pahlavas displaced them. To this house of Eucratides belonged Antialkidas, who is famous as the king who sent Heliodorus to the court of the king of Besnagar.
Heliodorus erected a Garuda pillar at Besnagar and etched an inscription in which he professes to be a follower of Vasudeva. In the Punjab, the rulers of the Euthydemus line continued till they were overthrown by the Shakas in the first century BC. Strato was one of the last kings known to us.