The Persian Gulf is located in the southern part of the Iranian plateau in the southwestern part of Asia. The Persian Gulf is formed by the advance of the Oman Sea and the Indian Ocean on the land of this region.

Historical documents show that the Persian Sea has existed since ancient times, and is one of the oldest seas used. Many great civilizations such as the ancient Elamite civilization and the Mesopotamian civilizations were formed along the sea. The Elamite civilization is the symbol of 50 centuries of Iranian civilization and was the largest civilization in Southwest Asia in ancient times. The Persian Gulf as one of the most important regions of the Middle East is important in many ways. Having energy resources (oil and gas) has doubled the economic importance of the Persian Gulf. In this article, an attempt has been made to present the findings of studies conducted in relation to the historical background of the Persian Gulf. 

Historical records 

Historical documents indicate that the Persian Gulf has existed since ancient times, and its name has been used in various historical periods. The Gulf has been called the “Persian Sea” in early texts, and the term “Persian Gulf” was adopted later. Scholars such as Herodotus, Strabo, and Pliny the Elder referred to it as the “Persian Gulf.” In Roman and Greek sources, it was sometimes called the “Persian Sea” or “Persian Gulf.” Latin translations of Greek terms led to the modern names used worldwide: Persian Gulf in English, Golfe Persique in French, Persischer Golf in German, and so on.

The 10th of Ordibehesht (second Iranian month) is remembered in Iranian history as a tribute to the sacrifice and selflessness of the proud Iranian nation against colonizers. On such a day, the occupying Portuguese, after 117 years of brutal rule over Iran’s southern coasts (April?21,?1622?CE), were expelled from the region following the bravery of the Iranian forces led by Amir al?Mamalik of Fars (Imam Qoli?Khan). Shah?Abbas the Great, in 1621?CE, succeeded in driving the Portuguese from Hormuz; this day (the 10th of Ordibehesht) will forever remain a permanent part of Iranian history. Given the importance of the Persian Gulf, efforts have been made to provide some historical documents related to the warm and azure waters of the Persian Gulf.

Ancient Greek accounts

Ancient Greek geographers like Thales, Anaximenes, Hecataeus, and Strabo used the term “Persian Gulf” in their works. Strabo, in particular, described the Gulf as “Pérsikos sinós” (Persian Gulf). The Greeks also referred to it as “Parsa dár?” or “Parsa d?rays.” Their writings indicate that the Persian Gulf was recognized as a distinct body of water, separate from the Arabian Sea.

Latin and European usage
Latin authors adopted the Greek term, rendering it as “Pérsikos sinós” or “Sinus Persicus.” Later, European cartographers and scholars translated the name into their languages: Persian Gulf (English), Golfe Persique (French), Persischer Golf (German), and so on. These names have become standard in international maritime charts and legal documents.

The Persian Gulf in Ancient Persia

During the Achaemenid period (550–330?BC), the Persian Gulf was known as the “Parsa d?rays” or “Parsa d?r?.” Inscriptions from King Darius?I describe a canal from the Gulf to the Persian Sea. The Achaemenids considered the Gulf a vital maritime corridor, linking the Persian Empire with the Indian Ocean.
The Parthian and Sassanid empires continued to view the Persian Gulf as a crucial trade route. They built ports and islands such as Qeshm, Kish, and Lark to facilitate commerce. The Persian Gulf’s strategic importance was recognized in both military and commercial contexts.

The Persian Gulf in the Islamic Period

During the Islamic era, the shores of both sides of the Persian Gulf fell to the Muslims. The Deylamites, a branch of the Iranian dynasty, once again conquered the entire island, ports, and waters of the Persian Gulf. Oman and its ports and islands were annexed to the Al-e Buyeh dynasty by Ali Emad al-Daula and Ahmad Mazdar al-Daula. The rule of Al-e Buyeh dynasty reached its peak during the reign of Emad al-Daula, and throughout their rule, Fars and Hormozgan was under their jurisdiction. After the Deylamites, the Seljuks gained control over the Persian Gulf and the Sea of Oman. The rulers of Fars established their authority over Oman, Bahrein, and the shores and islands of the Persian Gulf and the Sea of Oman.
Later, the Seljuks, Mongols, and Timurid rulers also controlled the Persian Gulf’s coast. The Portuguese, in the 16th century, seized the Strait of Hormuz and established a foothold on Qeshm Island. Safavid king Shah Abbas I expelled the Portuguese from the Persian Gulf, restoring Persian control.

Nader Shah Afshar gained control over all the coasts and islands of the Persian Gulf in 1728 CE by expelling the Afghans from Iran. 
Karim Khan Zand, after defeating his rivals, dominated the islands and ports of the Persian Gulf. 

Modern period

In the 20th century, the Persian Gulf became a focal point of geopolitical interest. Iran, Saudi Arabia, Iraq, the United Arab Emirates, Oman, and Qatar share maritime borders with the Persian Gulf. The discovery of vast oil reserves in the mid-20th century transformed the region’s economic importance.

Modern geographical features of Persian Gulf

Area: Approximately 225,000?km²

Length: 900?km

Average width: 180–200km

Average depth: 50?m

Maximum depth: ~100m

Width of Strait of Hormuz: 56km

Depth of Strait of Hormuz: Varies from 36?m near Lark to 180?m near the Iranian coast.

Strait of Hormuz 

The Strait of Hormuz, a narrow waterway, connects the Persian Gulf with the Arabian Sea. It has significant economic and strategic importance due to the passage of oil and gas shipments.
The Strait of Hormuz is one of the most sensitive and critical water passages in the current era, located in the political territory of Hormozgan province. This horseshoe-shaped strait is 187 kilometers long. Also, several small and large islands such as Abu Musa, the Greater and Lesser Tunbs, Siri, Kish, Qeshm, Lavan, Lark, Hormuz, Hendurabi, and Kharg are located within the coastal waters of this province.

Maritime borders and ports
The Persian Gulf is bordered by Iran, Iraq, Saudi Arabia, Qatar, the United Arab Emirates, Bahrain, and Oman. Major ports include Bandar Abbas, Bushehr, Mahshahr, Khorramshahr, and Bandar Abbas in Iran, and Sharjah, Dubai, and Abu Dhabi in the UAE. Key islands such as Qeshm, Kish, Lark, and Hormuz serve as strategic military and commercial hubs.

Summary
The Persian Gulf has been a vital maritime corridor since antiquity. Its strategic importance has been recognized by empires ranging from the Achaemenids to the government of Islamic Republic of Iran. Its oil and gas resources, coupled with its position as a chokepoint for global shipping, make it one of the most geopolitically significant regions in the world.

By Habibollah Mahmoudian, PhD, is a specialist in prehistoric archaeology