After the conquests of Asia and Africa by Alexander the Great the Greeks adopted a blended culture. This culture was known as Hellenistic. The common language was known as Koine. It was a blend of Greek and Persian languages. The greatest city of the Greek empire was known as Alexandria. It was a very rich city located in Egypt. Royal palaces were built and Alexander's tomb was located there. A large lighthouse called Pharos that reflected light from a fire. In Alexandria were two great sources of knowledge Alexander's library and museum. These were the greatest sources of knowledge in all of the ancient world and brought visitors from around Europe, Asia and Africa. The Hellenic empire also developed different studies of astronomy, mathematics and physics. The forerunner's of Hellenic math were Archimedes and Euclid.