The plaque dedicated to Princess Sophia Duleep Singh, who was Queen Victoria's goddaughter and the daughter of the last ruler of the Sikh empire, was unveiled at her former home at Faraday House, Hampton Court, southwest London.

The princess was a member of the Women's Social and Political Union (WSPU) - the militant group led by Emmeline Pankhurst - and used her status and wealth as a member of the Punjabi royal family to support the cause of gender equality.

Film director Gurinder Chadha, actress Meera Syal, Professor Helen Pankhurst and Lord Singh were among the guests who attended the ceremony.

Anita Anand, author of Sophia: Princess, Suffragette, Revolutionary, said: "We owe Sophia such a debt of gratitude because without her courage and the courage of women like her you can't take it for granted that we would have the right to vote in this country.

"She was one of those bloody-minded women who never do what they are supposed to do.

"Women's history falls through the cracks and women of colour plummet through them," Ms Anand added.

"Her fortitude is something that should not be forgotten, and it is only right that we should see it in a plaque so that young girls when they walk past might ask, 'who was she?'"

Born in 1876, Sophia and her sisters Bamba and Catherine grew up in Folkestone and Brighton with their guardian Arthur Craigie Oliphant and his family.

Sophia's early childhood was turbulent with her father, Maharaja Duleep Singh, abandoning his young family to live in Paris and her mother, Bamba Muller, suffering from alcoholism.

Queen Victoria later granted Faraday House to the sisters in 1896 where they lived as adults.

From 1909, Sophia was active in the Richmond and Kingston-upon-Thames district branches of the WSPU.

She sold copies of The Suffragette newspaper at her pitch outside Hampton Court Palace, and once threw a suffragette poster reading "Give women the vote!" at Prime Minister Herbert Asquith's car at the state opening of Parliament in 1911.

Read more:
The Suffragettes - the women who risked all to get the vote

Sophia was also a member of the Women's Tax Reform League (WTRL), a movement that refused to pay various taxes, insurances and licence fees under the motto "No Vote, No Tax".

The princess was summoned to court several times and fined for abstaining from personal licences on jewellery, dogs and a carriage.

Sophia also attended "Black Friday" on 18 November 1910, when more than 300 suffragettes marched from Caxton Hall to Parliament Square and demanded to see the prime minister.

The demonstration descended into violence when the prime minister refused to see the suffragettes, and police assaulted the women who refused to leave.

Five years later, she was one of 10,000 women who took part in the Women's War Work Procession led by Ms Pankhurst.

Sophia also supported the Indian Women's Education Association in London and volunteered during both world wars - nursing Indian soldiers in the First World War and housing evacuees in the Second World War.