TEHRAN–Some of the earliest archaeological expeditions to Iran began in the mid-19th century, when British and French archaeologists investigated Susa and its surroundings in southwestern Iran.

In the decades that followed, excavations were conducted primarily by American, British, French, German, and Iranian-sponsored expeditions throughout Iran.

However, many of these early excavations have proven effective in unearthing a wealth of artifacts, architecture, and information relating to the region's ancient civilizations. However, due to the unsystematic techniques used in these early excavations, several sites had to be reexamined with scientific methods.

By the late 1930s, archeology took a back seat as resources were allocated to the war effort in Europe during World War II. But once political stability was achieved, several foreign-sponsored excavations continued unabated in Iran until the Islamic Revolution in 1979.

A year later, when the war between Iran and Iraq broke out, work in the archaeological field stopped until the early 1990s. In recent years, the pace of excavations has increased, along with the skill and accuracy of the researchers involved.

On the occasion of International Archaeology Day, celebrated on October 15, here is a brief synopsis of Iranian history compiled by the Milwaukee Public Museum:

The earliest evidence of human occupation within the Iranian plateau comes primarily from archaeological remains in caves and rock shelters that date to the Early Paleolithic, circa 45,000 BC.

These early inhabitants lived in a very dynamic environment that required a mobile hunter-gatherer lifestyle. It was only after a few thousand years that these short-lived camps began to develop into longer-term sedentary settlements near rivers and freshwater springs. Some of the world's earliest open-air settlements are in Iran and date back around 10,000 years.

This period marks the beginning of the Neolithic revolution, characterized by the expansion of agricultural communities and increasing social complexity, with consequent innovations in material culture, in particular the development of pottery.

Around 5000 BC, people began mining and manipulating the region's abundant metal resources, especially copper. Known as the Chalcolithic, this period lasted until around 3500 BC, when metallurgy became much more sophisticated by adding tin to produce bronze, marking the beginning of the Bronze Age.

Over the next 2,000 years, bronze technology became the primary material for the production of high-ranking weapons and ships; meanwhile, pottery continued to be refined and elaborate. Around 1500 BC, iron began to be exploited alongside bronze for weapons production, marking the transition period to the Iron Age and subsequent cities/states that began to consolidate their influence over a wider region.

Some of these regional powers are known as the Elamites, whose capital was in the southwestern city of Susa, the Babylonians and Assyrians of Mesopotamia, the Hittites of Anatolia and the Scythians of the northern Caspian Sea. It was during this period that the first Indo-Iranians moved to the Iranian plateau and from which arose the first great empire of Iran, the Medes.

Median Empire (c. 728–550 BC)

The Median Empire is considered the first Iranian empire, whose central area was in the northwestern part of Iran, near the Caspian Sea. The influence of this civilization spread over a wide area, from western Turkey to northern Pakistan.

The Medians were united under Cyaxares, who was able to consolidate power among several tribal groups that routinely waged hostile campaigns against rival kingdoms, such as Assyria, Babylon, and Nineveh. It was not long, however, before Median influence waned and a new Iranian empire was born, known as the Achaemenids.

Achaemenid Empire (c. 550 - 330 BC)

The Achaemenid Empire was founded by Cyrus the Great and was the first Iranian political government from 559 BC to 330 BC. During this period, the Greeks named this Persian civilization, named after the Achaemenid capital in the southwestern city of Pars.

The Achaemenid Empire expanded into Central and Southwest Asia through a series of military campaigns. To the west, Cyrus defeated Lydia's king Croesus in 546 BC, who secured power in Armenia, Asia Minor and the Greek colonies. To the east, Cyrus defeated Partia and Bactriana. After conquering Babylon in 539 BC and releasing all the Jews who were being held captive, was mentioned in the book of Isaiah.

Darius I took control of the Empire after Cyrus' successor, his son, committed suicide. Like Cyrus, Darius became a powerful leader, pursuing the will of the Achaemenid Empire over a vast territory. After his death in 486 BC. However, by 300 BC, the empire was becoming vulnerable to the outside world and would soon fall to a powerful western power, Greece.

Seleucid Empire (c. 330 - 150 BC)

Under the leadership of the famous Macedonian soldier Alexander the Great, the Greek and Iranian peoples were united. As a result of a large influx of Greeks into Iran, they brought with them a Hellenistic artistic tradition, which ultimately influenced much of Iranian art and architecture during this period.

In the years following the death of Alexander the Great in 323 BC the vast empire was divided and placed under the power of its generals. One of these generals was Seleucus, who died at the end of the 4th century BC succeeded in consolidating much of Iran into what became known as the Seleucid Empire. In the year 247 BC. However, in 300 BC, Arsaces I led a revolt against the Seleucid government and later founded an independent dynasty known as the Parthians.

Parthian Empire (c. 250 BC–226 CE)

Like many of the empires before it, the Parthians became yet another influential Near Eastern empire between 247 BC and 226 CE. The Parthians managed to cultivate extensive trade relations with Central Asia and China; however, they came into significant conflict with the eastward expansion of the Romans.

On several attempts, the Romans tried to conquer the Parthian Empire but failed until the reign of the Roman Emperor, Trajan. In 116 CE, Trajan won battles in Armenia and Babylonia and eventually took over the Parthian capital in Susa, Iran. Shortly thereafter, Trajan’s successor Hadrian returned the territories back to their previous rulers. In 224 CE, the Parthian king was overthrown, and the new Sassanid dynasty was established.

Sassanian Empire (c. 226 CE -650)

Sassanian means dominion of the Aryans (Iranians). The Sassanian Empire is considered one of the most influential periods in Iran and the last great empire before the coming of Islam.

Sassanian influence can be seen in art from China and India. The Sassanian Empire tried to revive the Iranian culture and traditions and also tried to eradicate the Greek cultural presence in the region. The main religion during the Sassanian rule was Zoroastrianism, based on the teachings ascribed to the prophet, Zoroaster.

Religion placed a strong emphasis on the principles of Good and Evil. The end of the Sassanian period came in 631 CE when an area spanning from Spain to India underwent a permanent transformation under the influence of an emerging cultural and religious movement, known as the Islamic conquest.

Early Islam (c. 651 CE- 1000)

Between the years 660 CE to 750, Iran came under the authority of the Umayyad dynasty, which acted to consolidate Muslim unity through Islamic Law and Sharia.

By 750 CE, the Abbasid government, from its seat in the Mesopotamian city of Baghdad, began exerting its influence over the Iranian plateau. Nevertheless, over succeeding centuries of Islamic rule, semi-autonomous dynasties continued to control different regions of the country.

One of the most influential dynasties under the Abbasid government was the Tahrids. The Tahrid's capital was located in Merv, situated in the providence of Turkmenistan, east of the Caspian Sea. However, in 820 CE, the capital was moved to Nishapur (Neyshabur) in the Khorasan region of eastern Iran.

The Seljuks (c. 1000 CE- 1218)

Iran at this time was not influenced by Islamic art and architecture to the west, but rather was more influenced by Central Asia. In 1000 CE, the Seljuks led a campaign into Transoxia in Turkmenistan, which facilitated the establishment of greater Central Asian influence.

By the end of the 10th century CE, the Seljuks controlled the majority of Central Asia. Many cosmopolitan cities were subsequently established along the major thoroughfares of trade and communication, known as the Silk Road, leading from China to the Mediterranean.

The Mongols (c. 1218 - 1334)

Unified under the rule of Genghis Khan in the 13th century CE, these equestrian experts spread from the Central Asian country of Mongolia, thus becoming known as the Mongol invasion. The Mongols were an alliance of several tribes from the region and unified to form one of the largest empires the world has ever known.

Under their violent reign, they controlled a region from Eastern Europe to Indonesia. By 1294, the Mongol Empire was split into four different regions. One of the four dynasties under the Ilkhanate rule included Iran, as well as parts of Iraq, Afghanistan and Pakistan.

The Mongol Empire ended in 1334 under the rule of Genghis Khan's grandson, Mongke Khan. The widespread destruction left in the wake of this empire can be seen all over Iran in locations such as Rey and Susa.

AM