The power of the Saka rulers began to decline during the 2nd century CE after the Indo-Scythians were defeated by the Satavahana emperor Gautamiputra Satakarni.

[9][10] Indo-Scythian rule in the northwestern subcontinent ended when the last Western Satrap, Rudrasimha III, was defeated by the Gupta emperor Chandragupta II in 395 CE.

The Indo-Scythian war was triggered by the nomadic flight of Central Asians from conflict with tribes such as the Xiongnu in the second century CE, which had lasting effects on Bactria, Kabul and the Indian subcontinent and Rome and Parthia in the west.

Like the Scythians whom Herodotus describes in book four of his History (Saka is an Iranian word equivalent to the Greek Scythes, and many scholars refer to them together as Saka-Scythian), Sakas were Iranian-speaking horse nomads who deployed chariots in battle, sacrificed horses, and buried their dead in barrows or mound tombs called kurgans.

[29] According to these ancient sources, Modu Shanyu of the Xiongnu tribe of Mongolia attacked the Yuezhi (possibly related to the Tocharians, who lived in the eastern Tarim Basin) and evicted them from their homeland between the Qilian Shan and Dunhuang c. 175 BCE.

A tribe known to ancient Greek scholars as the Sacaraucae (probably from the Old Persian Sakaravaka, "nomadic Saka") and an allied people, the Massagetae, came into conflict with the Parthian Empire in Parthia between 138 and 124 BCE.

The Yuezhi tribes migrated east into Bactria after their defeat, from which they conquered northern India to establish the Kushan Empire.

[34] The mixed Scythian hordes who migrated to Drangiana and the surrounding regions later spread into north and south-west India via the lower Indus valley.

The Arsacid emperor Mithridates II (c. 123–88/87 BCE) pursued an aggressive military policy in Central Asia and added a number of provinces to the Parthian Empire.

[36] Following military pressure from the Yuezhi (predecessors of the Kushana), some Indo-Scythians moved from Bactria to Lake Helmond (or Hāmūn) and settled in or near Drangiana (Sigal).

[39]From petroglyphs left by Saka soldiers at river crossings in Chilas and on the Sacred Rock of Hunza in Pakistan, Ahmad Hassan Dani and Karl Jettmar [de] have established the route across the Karakoram mountains used by Maues (the first Indo-Scythian king) to capture Taxila from Indo-Greek King Apollodotus II.

[40] The first-century CE Periplus of the Erythraean Sea describes the Scythian territories: Beyond this region (Gedrosia), the continent making a wide curve from the east across the depths of the bays, there follows the coast district of Scythia, which lies above toward the north; the whole marshy; from which flows down the river Sinthus, the greatest of all the rivers that flow into the Erythraean Sea, bringing down an enormous volume of water (...) This river has seven mouths, very shallow and marshy, so that they are not navigable, except the one in the middle; at which by the shore, is the market-town, Barbaricum.

Before it there lies a small island, and inland behind it is the metropolis of Scythia, Minnagara; it is subject to Parthian princes who are constantly driving each other out ...[41]The Indo-Scythians established a kingdom in the northwest near Taxila, with two satraps: one at Mathura in the east, and the other at Surastrene (Gujarat) in the southwest.

[42] The presence of the Scythians in modern Pakistan and north-western India during the first century BCE was contemporaneous with the Indo-Greek kingdoms there, and they apparently initially recognized the power of the local Greek rulers.

Rajuvula apparently eliminated Strato II (the last Indo-Greek king) c. 10 CE and took Sagala, his capital city.

[46] The Yuga Purana describes an invasion of Pataliputra by the Scythians during the first century BCE, after seven kings ruled in succession in Saketa following the retreat of the Yavanas.

[47] After Azes' death, Indo-Scythian rule in northwestern India ended with the rise of the Indo-Parthian ruler Gondophares late in the first century BCE.

[33] Indo-Scythians continued to hold the Sistan region until the reign of Bahram II (276–293 CE), and held several areas of India well into the first millennium; Kathiawar and Gujarat were under Western Satrap rule until the fifth century.

Indo-Scythian coins continue Indo-Greek tradition by using the Greek alphabet on the obverse and Kharoshthi script on the reverse.

Several Gandharan sculptures show foreigners in soft tunics, sometimes wearing the pointed hat typical of the Scythians.

They wear pointed hoods or the Scythian cap; this distinguishes them from the Indo-Parthians, who wore a simple fillet over their bushy hair,[49] and which is worn by Indo-Scythian rulers on their coins.

In another relief, the same type of soldiers are playing musical instruments and dancing; in Gandharan art, Indo-Scythians are typically depicted as reveling devotees.

An Indo-Corinthian capital of a Buddhist devotee in foliage has been found which had a reliquary and coins of Azes buried at its base, dating the sculpture to c. 20 BCE.

Shakas are mentioned in the Purāṇas, the Manusmṛti, the Rāmāyaṇa, the Mahābhārata, the Mahābhāṣya, the Bṛhat Saṃhitā by Varāhamihira, the Kāvyamīmāṃsā, the Bṛhatkathāmañjarīi, and the Kathāsaritsāgara.

[64] The Mahabharata also alludes to the invasion of mixed hordes from the northwest, with prophetic verses that "...the Mlechha (barbaric) kings of the Shakas, Yavanas, Kambojas, Bahlikas ... shall rule the earth un-righteously in Kali Yuga ..."[65] A portion of Central Asian Scythians under Sai-Wang reportedly moved south, crossed the Pamir Mountains and entered Chipin (or Kipin) after crossing the Xuandu (懸度, Hanging Pass) above the valley of Kanda in Swat.

[72] The Scythian groups who invaded India and established kingdoms included, in addition to the Saka, allied tribes such as the Medii, Xanthii, and Massagetae.

The Periplus of the Erythraean Sea (c. 70–80 CE) documents a Scythian district in the lower Indus Valley, with Minnagra its capital.

The second-century BCE Scythian invasion of India was probably carried out jointly by the Saka, Pahlavas, Kambojas, Paradas, Rishikas and other allied tribes from the northwest.

[77][79] Viparite tada loke purvarupa.n kshayasya tat bahavo mechchha rajanah prithivyam manujadhipa mithyanushasinah papa mrishavadaparayanah Andhrah Shakah Pulindashcha Yavanashcha naradhipah Kamboja Bahlikah Shudrastath Abhira narottama.