Soon after, relieved by the death of Diodotus, Arsaces made peace and concluded an alliance with his son, also by the name of Diodotus; some time later he fought against Seleucos who came to punish the rebels, and he prevailed: the Parthians celebrated this day as the one that marked the beginning of their freedom
"And they also held Sogdiana, situated above Bactriana towards the east between the Oxus River, which forms the boundary between the Bactrians and the Sogdians, and the Iaxartes River. And the Iaxartes forms also the boundary between the Sogdians and the nomads.
...for if he did not yield to this demand, neither of them would be safe: seeing that great hordes of Nomads were close at hand, who were a danger to both; and that if they admitted them into the country, it would certainly be utterly barbarised.
"When I was in Bactria (Daxia)", Zhang Qian reported, "I saw bamboo canes from Qiong and cloth made in the province of Shu (territories of southwestern China). When I asked the people how they had gotten such articles, they replied, "Our merchants go buy them in the markets of Shendu (India)."
Upon his return, Zhang Qian informed the Chinese emperor Han Wudi of the level of sophistication of the urban civilizations of Ferghana, Bactria and Parthia, who became interested in developing commercial relationships with them:
Some of the Greek populations that had remained in northwestern India apparently converted to Buddhism:
Furthermore, according to Pali sources, some of Ashoka's emissaries were Greek Buddhist monks, indicating close religious exchanges between the two cultures:
"After having conquered Saketa, the country of the Panchala and the Mathuras, the Yavanas, wicked and valiant, will reach Kusumadhvaja ("The town of the flower-standard", Pataliputra). The thick mud-fortifications at Pataliputra being reached, all the provinces will be in disorder, without doubt. Ultimately, a great battle will follow, with tree-like engines (siege engines)."
"Then in the eighth year, (Kharavela) with a large army having sacked Goradhagiri causes pressure on Rajagaha (Rajagriha). On account of the loud report of this act of valour, the Yavana (Greek) King Dimi[ta] retreated to Mathura having extricated his demoralized army."
The Periplus further explains ancient Indo-Greek rule and continued circulation of Indo-Greek coinage in the region:
According to the Yuga Purana, the Yavanas thereafter will retreat following internal conflicts:
Therefore, Menander remains the likeliest candidate for any advance east of Punjab.
Around eight "western" Indo-Greek kings are known; most of them are distinguished by their issues of Attic coins for circulation in the neighbouring region.
Rudradaman (...) who by force destroyed the Yaudheyas who were loath to submit, rendered proud as they were by having manifested their' title of' heroes among all Kshatriyas.
sa 1 1 1 100 10 4 4 Prothavadasa di 20 4 1 1 1 Budhagosa danamu(khe) Saghorumasa sadaviyasa
"In year 318, the day 27 of Prausthapada, gift of Buddhaghosa, the companion of Samghavarma"
And afterwards, taking delight in the wisdom of the Elder, he (Menander) handed over his kingdom to his son, and abandoning the household life for the house-less state, grew great in insight, and himself attained to Arahatship!
But when one Menander, who had reigned graciously over the Bactrians, died afterwards in the camp, the cities indeed by common consent celebrated his funerals; but coming to a contest about his relics, they were difficultly at last brought to this agreement, that his ashes being distributed, everyone should carry away an equal share, and they should all erect monuments to him.Sima Qian, "Records of the Great Historian", trans. Burton Watson, p. 236.
The Milinda Panha, in the questions of Nagasena to king Menander, provides a rare glimpse of the military methods of the period:
Now one day Milinda the king proceeded forth out of the city to pass in review the innumerable host of his mighty army in its fourfold array (of elephants, cavalry, bowmen, and soldiers on foot).
The royal city of the Calingae (Kalinga) is called Parthalis. Over their king 60,000 foot-soldiers, 1,000 horsemen, 700 elephants keep watch and ward in "procinct of war."
The Indo-Greek armies would be conquered by Indo-Scythians, a nomadic tribe from Central Asia.
There is an important evolution of coin shape (round to square) and material (from gold to silver to brass) across the territories and the periods, and from Greek type to Indian type over a period of nearly 3 centuries. Also, the quality of coinage illustration decreases down to the 1st century AD. Coinage evolution is an important point of Indo-Greek history, and actually one of the most important since most of these kings are only known by their coins, and their chronology is mainly established by the evolution of the coin types.