After returning to England, he served as a Liberal Party Member of Parliament (MP) for Nottingham East from 1906 to January 1910.

As he retired, he was appointed a Knight Commander of the Order of the Star of India (KCSI) in the 1902 Coronation Honours list published on 26 June 1902,[6][7] and invested as such by King Edward VII at Buckingham Palace on 24 October 1902.

On his return to England, Cotton was elected Liberal Party Member of Parliament (MP) for Nottingham East in 1906.

[10] Cotton met and married Ryan having seen a picture of her taken by pioneering photographer Julia Margaret Cameron.

[12] He was an active writer and activist on behalf of Indian rights until the end of his life, despite ill health and financial difficulties.

It was aimed to draw attention of the ruling class for policy making in view of the great social, political and religious changes that were taking place in India at the time.

Sir Henry Cotton died at his home in St John's Wood, London, in October 1915.