Persepolis
Darius I built the greatest palace at Persepolis on the western side of platform. This palace was called the "Apadana". The King of Kings used it for official audiences. The work began in 518 BC, and his son, Xerxes I, completed it 30 years later. The palace had a grand hall in the shape of a square, each side long with seventy-two columns, thirteen of which still stand on the enormous platform. Each column is high with a square Taurus (bull) and plinth. The columns carried the weight of the vast and heavy ceiling. The tops of the columns were made from animal sculptures such as two-headed lions, eagles, human beings and cows (cows were symbols of fertility and abundance in ancient Iran). The columns were joined to each other with the help of oak and cedar beams, which were brought from Lebanon. The walls were covered with a layer of mud and stucco to a depth of 5 cm, which was used for bonding, and then covered with the greenish stucco which is found throughout the palaces.
Persian people
The ancient Persians were a nomadic branch of the Iranian population that, in the early 10th century BC, settled to the northwest of modern-day Iran. They were initially dominated by the Assyrians for much of the first three centuries after arriving in the region. However, they played a major role in the downfall of the Neo-Assyrian Empire. The Medes, another branch of this population, founded the unified empire of Media as the region's dominant cultural and political power in c. 625 BC. Meanwhile, the Persian dynasty of the Achaemenids formed a vassal state to the central Median power. In c. 552 BC, the Achaemenids began a revolution which eventually led to the conquest of the empire by Cyrus II in c. 550 BC. They spread their influence to the rest of what is called the Iranian Plateau, and assimilated with the non-Iranian indigenous groups of the region, including the Elamites and the Mannaeans.
At its greatest extent, the Achaemenid Empire stretched from parts of Eastern Europe in the west, to the Indus Valley in the east, making it the largest empire the world had yet seen. The Achaemenids developed the infrastructure to support their growing influence, including the creation of Pasargadae and the opulent city of Persepolis. The empire extended as far as the limits of the Greek city states in modern-day mainland Greece, where the Persians and Athenians influenced each other in what is essentially a reciprocal cultural exchange. Its legacy and impact on the kingdom of Macedon was also notably huge, even for centuries after the withdrawal of the Persians from Europe following the Greco-Persian Wars. The empire collapsed in 330 BC following the conquests of Alexander the Great, but reemerged shortly after as the Parthian Empire.