Hellenistic cities emerged after the conquests of Alexander the Great in the 4th century BCE, spreading Greek culture across the Mediterranean and Near East. These cities were characterized by their urban planning, featuring grid layouts, public spaces like agoras, and monumental architecture, reflecting a blend of Greek and local influences. Key examples of Hellenistic cities include Alexandria in Egypt, known for its famous library, and Antioch in Syria, which became a cultural hub. These cities facilitated trade, cultural exchange, and the spread of Hellenistic philosophy, contributing to the rich tapestry of ancient civilization.