National Persian Gulf Day is observed in Iran every April 30, particularly in coastal cities along the Persian Gulf. This annual observance was first suggested in January 2004 and officially established in July 2005. The date commemorates the anniversary of Abbas I of Persia's successful military campaign in April 1622, during which he expelled the Portuguese from Hormuz Island. The Persian Gulf, a Mediterranean sea between Iran and the Arabian Peninsula, has a name that has been historically disputed, with Iran advocating for the name Persian Gulf, reflecting its historical ties to the Persian Empire. The Persian Gulf Online Organization (PGO) plays a significant role in promoting this name and the observance itself. Celebrations typically include ceremonies that highlight the cultural and historical significance of the region.