Yavana was the name of one of the sons of Maharaja Yayati who was given the part of the world known as Turkey to rule. Therefore the Turks are Yavanas due to being descendants of Maharaja Yavana. The Yavanas were therefore kshatriyas (kings), and later on, by giving up the Vedic culture, they became mleccha-yavanas spreading across modern Europe (Mlecchas are regarded as non-vedic or those who left vedic system of lifestyle). Descriptions of the Yavanas are in the Mahabharata (Adi-parva 85.34). Another prince called Turvasu was also known as Yavana, and his country was conquered by Sahadeva, one of the Pandavas. The western Yavana joined with Duryodhana in the Battle of Kurukshetra under the pressure of Karna. It is also foretold that these Yavanas also would invade India in the Kaliyuga which later proved to be true in 326 BC afterwards. (Srimad Bhagavatam (Bhagavata Purana) 2.4.18)
abhira-sumbha yavanah khasadayah
ye ‘nye ca papa yad-apasrayasrayah
sudhyanti tasmai prabhavishnave namah ||
Translation : Kirata (tribals in central india), Huna (Chinese), Andhra (South Indian Kings), Pulinda (central indian kings), Pulkasa (Russians), Abhira (Sindh province kings), Sumbha, Yavana (Greeks and Turks), members of the Khasa (Mongolian) races and even others addicted to sinful acts can be purified by taking shelter of the devotees of the Lord (Krishna), due to His being the supreme power. I offer my respectful obeisances unto Him.
KalaYavan II was a Yavana/Yona/Greek ruler of western province (present afghanistan) during Mahabharat times and he was burnt alive due to a trick played by Krishna with Muchukunda
Agathocles issued an intriguing range of bilingual coinage, displaying what seems to be Buddhist as well as Hinduist symbolism.Manufactured according to the Indian standard, using either Brahmi (ancient indian script), Greek or Kharoshthi (ancient script used in Gandhar kingdom : present day afghanistan & pakistan), and displaying symbols of the various faiths in India, tend to indicate a considerable willingness to accommodate local languages and beliefs, to an extent unseen in subsequent Indo-Greek kings.
Six Indian-standard silver drachmas were discovered at Ai-Khanoum (Afghanistan) in 1970, which depict Hindu deities such as Vasudeva-Krishna, Balarama-Sankarshana, Lakshmi etc.