The "Rial" is a currency unit used in several countries, primarily in the Middle East. Its origin can be traced back to the Spanish term "real," which means "royal." Here's a summary of the rial's history in some of these countries:

• Iran: The Iranian rial (IRR) has a long history dating back to the 18th century. More recently, Iran introduced the "toman" to address inflation.
• Oman: The Omani rial (OMR) was established in 1970.
• Yemen: The Yemeni rial (YER) has been in use since the unification of Yemen in 1990.
• Qatar: The Qatari riyal (QAR) was adopted in 1966.
• Saudi Arabia: The Saudi riyal (SAR) is the current currency, introduced in 1961.
• Bahrain: While the Bahraini dinar (BHD) is the official currency, the term "rial" has also historically been used.