In the 320s BCE, Alexander the Great captured the city of Bagram and established a fortified colony named Alexandria of the Caucasus. The new town had brick walls reinforced with towers at the angles. The central street was bordered with shops and workshops. After his death in 323 BC, the city passed to his general Seleucus, who traded it to the Mauryan Dynasty of India in 305 BC. After the Mauryans were overthrown by the Sunga Dynasty in 185 BC, the Greco-Bactrian Kingdom invaded and conquered Northwestern India (Present Day Pakistan) with an army led by Demetrius I of Bactria. Alexandria became a capital of the Eucratidian Indo-Greek Kingdom after they were driven out of Bactria by the Yuezhi in 140 BC. Bagram (Kapisa) became the summer capital of the Kushan Empire in the 1st century, whereas their winter capital was in Peshawar. The emperor Kanishka started many new buildings there. The central palace building yielded a very rich treasure, dated from the time of emperor Kanishka in