for almost two centuries, starting from the reign of Darius the Great (522–485 BC). The first major conflict erupted when Alexander the Great overthrew the Achaemenid Empire in 334 BCE and marched eastwards. After defeating King Porus in the fierce Battle of the Hydaspes (near modern Jhelum), he conquered much of the Punjab region. But his battle weary troops refused to advance further into India to engage the formidable army of the Nanda Dynasty and its vanguard of elephants, new monstrosities to the invaders. Therefore, Alexander proceeded southwest along the Indus valley. Along the way, he engaged in several battles with smaller kingdoms before marching his army westward across the Makran desert towards modern Iran. Alexander founded several new Macedonian/Greek settlements in Gandhara and Punjab. As Alexander the Great's Greek and Persian armies withdrew westwards, the satraps left behind by Alexander were defeated and conquered by Chandragupta Maurya, who founded the Maurya Empire, which ruled the region from 321 to 185 BC. The Mauryas Empire was itself conquered by the Shunga Empire, which ruled the region from 185 to 73 BC. Other regions such as the Khyber Pass were left unguarded, and a wave of foreign invasion followed. The Greco-Bactrian king, Demetrius, capitalised and conquered southern Afghanistan and Pakistan around 180 BC, forming the Indo-Greek Kingdom. The Indo-Greek Kingdom ultimately disappeared as a political entity around 10 AD following the invasions of the Central Asian Indo-Scythians. Their empire morphed into the Kushan Empire who ruled until 375 AD. The region was then conquered by the Persian Indo-Sassanid Empire which ruled large parts of it until 565 AD. Muslim conquests In 712 CE, a Syrian Muslim chieftain called Muhammad bin Qasim conquered most of the Indus region (stretching from Sindh to Multan) for the Umayyad Empire. In 997 CE, Mahmud of Ghazni conquered the bulk of Khorasan, marched on Peshawar in 1005, and followed it by the conquests of Punjab (1007), Balochistan (1011), Kashmir (1015) and Qanoch (1017). By the end of his reign in 1030, Mahmud's empire extended from Kurdistan in the west to the Yamuna river in the east, and the Ghaznavid dynasty lasted until 1187. In 1160, Muhammad Ghori conquered Ghazni from the Ghaznavids and became its governor in 1173. He marched eastwards into the remaining Ghaznavid territory and Gujarat in the 1180s, but was rebuffed by Gujarat's Solanki rulers. In 1186–87, he conquered Lahore, bringing the last