Henry Martyn Clark was born in 1857, in Peshawar. He was of Afghan descent. His mother passed away during the 1857 mutiny. After losing his mother, he was adopted by the famous missionary Robert Martyn Clark. The priest nurtured Henry Martyn Clark; he named him after himself and took care of his educational expenses. Clark was educated at the University of Edinburgh and received his MD in 1892.

In 1881 he was accepted by the Church Missionary Society to start the Amritsar Medical Mission as a Medical Missionary. He left for Amritsar to join his father on 4 February 1882.

Henry Martyn Clark openly challenged the Muslims for a debate. Hazrat Mirza Ghulam Ahmad (as) was at the forefront of accepting his challenge. Thus, the debate took place in Amritsar and later was published in a book form titled Jang-e-Muqadas (Holy War).

On 1 August 1897, Henry Martyn Clark filed a lawsuit of attempted murder against Mirza Ghulam Ahmad (as) with Deputy Commissioner Montagu William Douglas in Ludhiana. In this court case, he falsely tried to prove that Hazrat Mirza Ghulam Ahmad (as) sent a youth named Abdul Hamid to murder him; but his plan ultimately failed. In 1905, Henry Martyn Clark retired and settled himself in Edinburgh. In Edinburgh and other parts of England, he delivered his lectures.

At last, he passed away on 10 April 1916. He is buried in Edinburgh.

Tracing his family, the Ahmadiyya Archive & Research Centre came in contact with his great grandson, Jolyn Martyn Clark, living in Blackpool. Jolyn had the honour to have an audience with Hazrat Khalifatul Masih V (aa). He also spoke at Jalsa Salana UK 2012 in the presence of Hazrat Khalifatul Masih V.