Explanation:

The Kangra Fort is located 20 kilometers from the town of Dharamsala on the outskirts of the town of Kangra, India.
History
The Kangra Fort was built by the royal Rajput family of Kangra State (the Katoch dynasty), which traces its origins to the ancient Trigarta Kingdom, mentioned in the Mahabharata epic. It is the largest fort in the Himalayas and probably the oldest dated fort in India.
The fort of Kangra resisted Akbar's siege in 1615. However, Akbar's son Jehangir successfully subdued the fort in 1620. Kangra was at the time ruled by Raja Hari Chand Katoch of Kangra (also known as Raja Hari Chand II) Mughal Emperor Jahangir with the help of Suraj Mal garrisoned with his troops.
The Katoch Kings repeatedly looted Mughal controlled regions, weakening the Mughal control, aiding in the decline of Mughal power, Raja Sansar Chand-II succeeded in recovering the ancient fort of his ancestors, in 1789. Maharaja Sansar Chand fought multiple battles with Gurkhas on one side and Sikh King Maharaja Ranjit Singh on the other. Sansar Chand used to keep his neighboring Kings jailed, and this led to conspiracies against him. During a battle between the Sikhs and Katochs, the gates of the fort had been kept open for supplies.
The Gurkha army entered the opened scarcely armed gates in 1806. This forced an alliance between Maharaja Sansar Chand and Maharaja Ranjit Singh. Because of the insufficiency of the need within the fort after a long war and unable to procure any, the Gurkhas left the Fort. The Fort remained with the Katochs until 1828 when Ranjit Singh annexed it after Sansar Chand's death. The fort was finally taken by the British after the Sikh war of 1846.