In about 1000 to 1500 Oman made a resurgence by controlling the Indian Ocean and the trading routes from Africa, Arabia, and India. This resurgence was short-lived however and in the 1500s the Portuguese gained control over these same trade routes by successfully attacking Oman's coasts and ships. Portuguese rule over Oman lasted until 1624.
In the 1800s, Oman regained influence over the seas and moved their capital to the island of Zanzibar (off the coast of modern-day Tanzania), making parts of the East African coast colonies. By the late 1800s however, the Omani empire had divided between Oman itself and the African colonies. Near the same time the British arrived in the Persian Gulf and tried to end Oman's control over trade.
Although the British never turned Oman into a colony, the country was essentially under British control during much of the 1900s. During this time Oman was essentially divided into two areas: the coast and the interior. The latter filled with nomads and desert, while the prior was based on trade and the seas. These two groups warred with each other as the coasts were dominated by the Sultan and the interior sought freedom and the open desert, which was the traditional life they had lived for centuries. Despite eventually uniting the country, civil unrest continued as Oman isolated itself from the rest of the world during much of the 1900s; education rates stagnated, and healthcare lagged behind international standards.
In 1970 Qaboos, the Sultan's son took power in a bloodless coup. At the time Oman only had two primary schools, no secondary schools, two hospitals (run by American missions), and only 10 kilometers of sealed roads. This uphill battle for Sultan Qaboos was successfully overcome as today, Oman rightfully boasts one of the world's best road networks, increasing literacy and education rates, and improving healthcare.