Amritsar, the center of Sikhism, was founded in 1577 by Ram Das, the fourth Guru of the Sikhs, on land granted by the Mughal Emperor Akbar, and is the site of the Sikhs' most important place of worship, the Harmandir Sahib, or Golden Temple. Ram Das commissioned the excavation of the sacred pool known as Amrita Saras, meaning "pool of nectar," from which the city takes its name. Arjan, the fifth Guru of the Sikhs, built a temple on an island in the center of the pool, which was then accessible by a marble causeway. During the reign of Maharaja Ranjit Singh between 1801-39, the upper part of the temple was adorned with a copper dome covered with gold foil. Since then, the temple has been commonly known as the Golden Temple. The city became the center of the Sikh faith, and as the center of growing Sikh power, the city enjoyed a corresponding growth in trade. In 1849, the city was annexed to British India. In addition to being home to hundreds of thousands of Sikhs, Amritsar is the main pilgrimage site for Sikhs from other parts of India and other countries. The Golden Temple and its complex of adjoining buildings around the pool are the main focus for these pilgrims. Akal Takht, the highest center of authority in Sikhism and the headquarters of the Shiromani Akali Dal, the main Sikh political party in Punjab, is located on the west side, facing the causeway to the temple. The key office of the Shiromani Gurdwara Parbandhak Committee, which oversees the major Sikh gurdwaras, is located in the Teja Singh Samundri Hall on the north side.