Persian Gulf

*The Persian Gulf is a mediterranean sea in WesternAsia (Middle East). An extension of the Indian Ocean (Gulf of Oman) through the Strait of Hormuz, it lies between Iran to the northeast and the Arabian Peninsula to the southwest.[1] The Shatt al-Arab river delta forms the northwest shoreline... * https://en.wikipedia.org/wiki/Persian_Gulf

The bordering countries can be called the Gulf Kingdom-s.