The Vishnukundins established their capital on this 300‑ft hill. Some historians identify the early Vishnukundin rulers Indravarma and Madhavavarma‑I as having ruled from Keesaragutta or the nearby ancient city of Indrapura. They built a stone and brick fortification wall enclosing the settlement, along with brick temples, yaga shalas (prayer halls), and rock‑cut cisterns. The discovery of twelve Panchaloha Jain Tirthankara idols (4th–5th c.) proves that Jainism flourished alongside Shaivism under the Vishnukundins. The earliest Telugu inscription “Thalachuvanru” (5th c.) is carved in a rock cave on the hill.

In the 14th century, Tughlaq forces attacked and partially destroyed the temple complex. Many metal idols were hidden by priests to prevent desecration – which is why the 12 Jain Panchaloha idols were found buried at a depth of one foot in 2014.

The temple was rebuilt in the 18th century by local chieftains under the Asaf Jahi (Nizam) rule. Systematic excavations between 1975 and 1983 uncovered the Vishnukundin fort wall, brick temple foundations, and numerous artefacts. In the 1990s, the temple underwent extensive renovation including gopuram restoration. The 2014 discovery of the Jain Tirthankara idols occurred during conservation work.

Following the reorganisation of Telangana districts on 11 October 2016, Keesara was designated as the administrative headquarters of Medchal‑Malkajgiri district. An Integrated Collectorate Complex has been established near the Outer Ring Road (ORR) in Keesara to serve the general public. This makes Keesaragutta not only an ancient religious centre but also a modern hub of governance.

After slaying Ravana – a Brahman and great Shiva devotee – Lord Rama sought to atone for Brahmahatya. He chose this hill and sent Hanuman to Varanasi to bring a Shiva Lingam. When Hanuman was delayed, Lord Shiva himself appeared and presented a Swayambhu (self‑manifested) Lingam, which Rama installed. This lingam is called Ramalingeswara and is the main deity of the temple.

Hanuman returned with 101 lingams only to find that the installation had already taken place. Aggrieved, he threw all 101 lingams across the hillside. To this day, numerous small lingams are scattered around the temple – visible proof of the legend. Lord Rama then ordained that Hanuman must be worshipped first before approaching the main Swayambhu Lingam. Rama also named the hill Kesarigiri (after Hanuman, son of Kesari), which evolved into Keesara / Keesaragutta.

Maha Shivaratri (February/March) draws tens of thousands of devotees for night‑long vigils. Karthika Masam (October–November) sees daily deepotsavam (lamp offerings). Monthly Pradoshams (13th lunar day) are highly auspicious.

The temple celebrates annual Brahmotsavams over several days (usually March–April), including Dwajarohana (flag hoisting), processions, rathotsavam (chariot festival), theerthavari (holy bath), and Rama Navami re‑enactments.

As ordained by Lord Rama, every devotee must first visit the Hanuman shrine before approaching the Swayambhu Lingam – a tradition strictly followed.