Peter Stark Lumsden was born at Belhelvie Lodge, Belhelvie, Aberdeenshire, on 9 November 1829. He was trained at Addiscombe Military Seminary from the age of 20, and entered the East India Company's Bengal Army in 1847 as an ensign in the 60th Bengal Native Infantry. Between 1852 and 1857 he served on the North-West Frontier in five expeditions against native tribes: the Mohmunds, the Ootman Khel, the Bori Afridis and the Miranzais. He was mentioned in despatches five times and awarded the special thanks of the Local and supreme Governments. From 1857 to 1858 he accompanied a special peace-finding mission to Kandahar with his brother Harry Lumsden. He received thanks from the Government for his work, but returned to India to take part in the suppression of the Indian Mutiny. Lumsden next joined the Central India Field Force at Gwalior under General Sir Robert Napier, and, as assistant quartermaster general under Major-General Hugh Rose, shared in the pursuit and capture of Tantya Tope in 1859, when he was again mentioned in despatches.