Oman is an Arab country on the southeastern coast of the Arabian Peninsula. Holding a strategically important position at the mouth of the Persian Gulf, the country shares land borders with the United Arab Emirates to the northwest, Saudi Arabia to the west, and Yemen to the southwest, and shares marine borders with Iran and Pakistan. The coast is formed by the Arabian Sea on the southeast and the Gulf of Oman on the northeast. The Madha and Musandam exclaves are surrounded by the UAE on their land borders, with the Strait of Hormuz (which it shares with Iran) and Gulf of Oman forming Musandam's coastal boundaries.
From the late 17th century, the Omani Sultanate was a powerful empire, vying with Portugal and Britain for influence in the Persian Gulf and Indian Ocean. At its peak in the 19th century, Omani influence or control extended across the Strait of Hormuz to modern-day Iran and Pakistan, and as far south as Zanzibar (today part of Tanzania, also former capital). As its power declined in the 20th century, the sultanate came under the influence of the United Kingdom. Historically, Muscat was the principal trading port of the Persian Gulf region. Muscat was also among the most important trading ports of the Indian Ocean. Oman's official religion is Islam.