Muscat is the capital and largest city of the Sultanate of Oman. The city lies on the Arabian Sea along the Gulf of Oman and is in the proximity of the strategic Straits of Hormuz. The rocky Western Al Hajar Mountains dominate the landscape of Muscat. Known since the early 1st century CE as an important trading port between the west and the east, Muscat was ruled by various indigenous tribes as well as foreign powers such as the Persians and the Portuguese Empire at various points in its history. A regional military power in the 18th century, Muscat's influence extended as far as East Africa and Zanzibar. Since the ascension of Qaboos bin Said as Sultan of Oman in 1970, Muscat has experienced rapid infrastructural development that has led to the growth of a vibrant economy and a multi-ethnic society.