Short answers, pulled from the story.
The Indo-Greek Kingdom began in 200 BC when Demetrius I crossed the Hindu Kush mountains and ended around 10 AD following the invasions of the Indo-Scythians. This period spans approximately 210 years of Greek rule in South Asia.
Demetrius I was the first Greek general to enter the Indian subcontinent in 200 BC with an army wearing elephant-scalp helmets. He was the son of Euthydemus I and established a permanent foothold that evolved into the Indo-Greek Kingdom.
Menander I, also known as Milinda, was the Indo-Greek king who converted to Buddhism and ruled from the capital at Sagala in the Punjab. His dialogue with the sage Nagasena is recorded in the Milinda Panha, and his death is described as being similar to the Buddha's passing.
The Indo-Greeks ruled from regional capitals including Taxila, Sagala, and Pushkalavati, with evidence of their presence in Mathura dating to the 116th year of the Yavana era around 70-60 BC. Archaeological excavations in Mathura have revealed terracotta figurines of helmeted soldiers and inscriptions from the Mitra and Datta dynasties.
The decline of the Indo-Greek Kingdom was precipitated by the rise of the Shunga Empire around 185 BC and the subsequent invasions of nomadic tribes from the north. The kingdom disappeared as a political entity around 10 AD after being overwhelmed by the Indo-Scythians, though Greek populations remained under later rulers.
The Indo-Greeks created Greco-Buddhist art in the Gandhara region by combining Greek artistic techniques with Buddhist religious themes. This unique style influenced the development of Buddhist art across Asia and is visible in the coins and sculptures produced during their rule.