The Tirumala hills are the world's second oldest rock mountains.There is no clear history on the origin of the temple of Lord Venkateshwara, but it was maintained and upgraded by various kingdoms. These include the Pallava Kingdom around 9th Century AD, Chola Kingdom around 10th century AD and the latest one being Vijayanagara Empire around 14th to 15th century AD. It was during the rule of Vijayanagara Empire that the temple received increased contributions.The site was an established center of Vaishnavism around 5th century A.D. during which Tirupati was praised by Alvars (Vaishnava saints); belonging to the Bhakti movement in Dravidian Land, who were known for their poems and literary works on Lord Venkateswara. Tirupati's significance in Southern Vaishnava tradition is next only to Srirangam, and the temple rites were formalized by the Vaishnavite saint Ramanujacharya himself, in the 11th century AD.Tirupati survived the Muslim invasions not only from South India but also from the British two times, unlike other temples such as the Meenakshi temple in Madurai and Ranganathaswamy Temple in Srirangam. It is believed that during the invasions the deity of Sriranganatha from Srirangam was brought to Tirupati for safekeeping. To commemorate this event, a hall in Tirupati is still known as the Ranganatha Mandapam.Tirupathi is the one of the most protected shrines in the world.The Madras legislature passed a special act in 1933 whereby the Tirumala Tirupati Devasthanam (TTD) committee was invested with powers of administration and control through a commissioner appointed by the Government of Madras. A Ryot Advisory Council was formed for the management of the estates of the TTD, and was assisted by a Religious Advisory Council with regard to religious matters.