A manuscript written by Abu Eshaq Ibn Mohammad Estakhri in the fourth century AH is one of the oldest existing documents showing historic name of Persian Gulf.

In this work, Estakhri has named today’s Persian Gulf, sea of Oman, some great parts of the Indian Ocean as sea of Persia. He has sometimes extended this sea to the mainland China.

Also, there are some old political letters at Imam Reza holy shrine’s document center which show usage of the name of Persian Gulf in ancient times. Some of these political letters turn back to the era of Ghajar dynasty.

The oldest of these documents belongs to 1822 and the period of Muzaffar al-Din Shah Qajar in which the name of Persian Gulf is clearly mentioned in Persian, German and English languages.

Also, conclusion of a contract between Mohammad Zaki Khan, governor of Fars, and British border guard in India regarding mutual cooperation in the ports and islands of the Persian Gulf and presence of British forces in those areas which was signed in 1822 is another old document of this kind.

The letter written by Shipping Company of the Netherlands to Seyyed Jalaledin Tehrani in 1985 alongside the complaint letter of Iranians of Kuwait to Sheikh Mohammad Khalesi regarding misbehavior of the governor of Najd toward Iranians living in Kuwait as well as the letter regarding the dominance of foreigners in the Persian Gulf Islands in 1923 are some other historic documents which contain the name of the water body as Persian Gulf.

Hossein Qoli Khan Nizam al-Saltaneh’s telegraphic order to Shokat al-Mulk to seize the convoy carrying weapons from Persian Gulf to Afghanistan dated 1908, a piece of story from al-Watan newspaper containing a historical document from the letter of Sheikh al-Sabah, Emir of Kuwait, specifying "Persian Gulf" in 2006, and a license issued by the British government in the Persian Gulf related to the transportation of merchandise from Bushehr port to Iran for Mohammad Shafi, a merchant from  Kazeroun, dated 1899, are other examples of historical texts containing Persian Gulf. 

Also, among other works containing name of the Persian Gulf, we can refer to a map gifted by the Austrian president Thomas Klestiel to Ayatollah Khamenei. This map is being kept at the Museum of Leader’s Gifts of the holy shrine.

Two geographical globes made in 1845 and 1850 in England contain name of Persian Gulf on them.