A majority of medieval forts in the Garhwal Himalayas of Uttarakhand were strategically built to form clusters. These networks of multiple forts enabled the then rulers to easily relay information signals using smoke and fire when under enemy attack, a recent archaeological survey has concluded.

The forts, dating back to the 8th century CE, were built at diverse altitudinal zones like valleys, along the ridges and prominent hilltops, some standing more than 3,000 metres above Mean Sea Level (MSL) in the Garhwal Himalayas.

The study, led by researchers at Hemvati Nandan Bahuguna Garhwal (Central) University, has identified 193 sites — having either intact or ruins of forts and fortalices spread along the north, east and southern regions of the Garhwal Himalayas.

Since the 15th century, the region has been known as Garhwal, a name it gets after the several Garhs (forts) found in this heavily mountainous region.

The study, originally published in Antiquity (Journal of Cambridge University Press) and Research Highlights (Nature), hypothesised that these well networked forts were built either during or after the downfall of the Katyuri dynasty, the rulers between 8th and 12th century CE.

“While there is still little archaeological or historic evidence as to which dynasty ruled and built these forts in the Garhwal Himalayas, our results from carbon dating process have revealed that the construction of these forts could have started around the 8th century CE,” Nagendra Singh Rawat, lead author and archaeologist at the Department of History and Archaeology at Garhwal University, told The Indian Express.

Since 2009, using toposheets and tools like GPS and GIS, Rawat undertook a number of field surveys and visits for six years. Physical visits were performed at 57 fort sites. This multidisciplinary study, along with co-authors Devidutt Chauniyal, Department of Geography, Garhwal Central University and Tom Brugman, Aarhus University, Denmark, has now shed light on some of the lesser known facets of these forts.

This is arguably the first of its kind database with satellite images revealing the intricate network of 193 sites from the region. A total of 36 major forts and 12 prominent fort clusters have been identified. Very little scientific studies of the forts here have been undertaken, one of them being the 2004 excavation of the Chandpur Fort by the Archaeological Survey of India.

History suggests that between 700 CE and 800 CE, the rulers of the Katyuri dynasty divided this region into many small mandals or units for administrative purposes. However, as the dynasty began to politically weaken around the turn of the millennium, these units came under the rule of Garhpatis or chiefdoms, each of whom built individual forts.

Since the Garhwal Himalayas are located en route to many religious places, it often came under foreign attacks and faced enemy invasions, mainly led by the Nepalese and the Tibetans.

The invasion by Askochalla and Krachalla, two Nepalese kings during 1100–1200 CE, is considered among the first foreign attacks here.

With most of the forts are located at high altitudes, experts believe that rulers back then could have resorted to visual communication to relay information to chiefdoms located at considerable physical distances.

“Geographically, the forts were built away from one another. But the rulers back then ensured that they were surrounded with smaller fortalices, which primarily functioned as watchtowers. These fortalices were erected and positioned around 15 km periphery of a major fort. Numerous such fortalices then formed a strategic network, enabling them to relay information, particularly when invaded by enemies. Fire, smoke or similar light signals could have been the common means to convey messages,” said Prof Vinod Nautiyal, co-author from the Garhwal Central University.

Even till this day, multistoried, earthquake-resistant and fortified residential structures built using wood and stones stand intact, Rawat said. At some sites, temple remains dedicated to Shiva and some goddesses, too, have been discovered.

“A few sites had structures that were used for residential purposes, known as Kothas. Likewise, Sumers (traditional houses in Garhwal valley), with five to seven storeyes, had dedicated their topmost floor to house a local deity. Even today, some Kothas and Sumers are occupied by prominent local families,” said Rawat.

By the 15th century, King Ajaypal, the 37th king of the Parmar dynasty, consolidated all these multiple chiefdoms in the region into a single state. This is the present day Garhwal, which has unique socio-religious and folk traditions, the experts said.