 Complete the following phrase:  In 334 BC he invaded the Achaemenid Empire Persian Empire and began a series of campaigns that lasted 10 years. Following his conquest of Asia Minor modern-day Turkey, Alexander broke the power of Persia in a series of decisive battles, including those at Issus and Gaugamela. He subsequently overthrew King Darius III and conquered the Achaemenid Empire in its entirety. At that point, his empire stretched from the Adriatic Sea to the Indus River. Alexander endeavored to reach the ends of the world and the Great Outer Sea and 