Ranajor Singh Thapa was governor of Kumaun and Garhwal and commander of Jaithak Fort during Anglo-Nepalese war. He was born to BadaKaji Amar Singh Thapa. Ranajor set up position at Jaithak overlooking Nahan. On the night of 25 December, British and Indian native sepoys climbed to get into better position to attack at Ranajor's forces But the Nepalese thwarted British down the mountain side.
Major General Martindell ordered retreat and first war ended. When General Ochterlony came up with heavy forces and modern equipments, Nepalese were losing out. Badakaji Amar Singh Thapa was reluctant to surrender but then came the letter of fall of Almora by Governor of Kumaun, Bam Shah. Ranajor lost connection completely from his father and from Central Nepal. He was hopelessly and rigidly defending the position. By the time Grand Old Man Bhakti Thapa and position of Almoda fell, his father had to surrender with no support from Capital Kathmandu.
Ranajor on second campaign linked up at Sindhuli Gadhi in support of his father.