Erbil, also spelled Arbil, locally called Hewlêr by the Kurds, is the capital city of Iraqi Kurdistan and the most populated city in the Kurdish inhabited areas of Iraq. It is located approximately in the center of Iraqi Kurdistan region and north of Iraq.
The Erbil Citadel, also known as Hawler Castle, is an artificial mound and the historical city center of Erbil, located in what’s now the Kurdistan region of Iraq. The mound was slowly formed as a result of human occupation starting about 6,000 years ago, eventually rising 100 feet (30 meters) tall as mud-brick structures and other debris crumbled and compacted into the ground below. It’s now enshrined as a UNESCO World Heritage site, surrounded by a city of more than 850,000 people.
Over the millennia, Erbil has been ruled by such empires as those of the Sumerians, Assyrians, Babylonians, Medians, and Achaemenids and later the Sassanid Persians, Greeks, Parthians, Arabs, and Ottomans. Erbil was already an ancient city when Alexander the Great famously defeated the Persian king Darius III some 50 miles (80 km) northwest of it at the Battle of Gaugamela, also known as the Battle of Arbela (Erbil), in 331 BCE.