Daniel O'Connell has been commemorated with a London blue plaque, which was unveiled in his honour in Mayfair.
O'Connell was known as the Liberator after he battled for the right of Catholics to sit in British parliament.
The plaque was unveiled above high-end boutiques and restaurants of Albemarle Street in London.
The plaque marks his former home in the capital's fashionable and affluent Mayfair district.
Among those already honoured by the distinctive blue plates are John Lennon, Florence Nightingale, Charles Dickens, Karl Marx and Jimi Hendrix.
Outside the house, Professor Martin Daunton of English Heritage, which issues the honours, said O'Connell was arguably the Mandela or Mahatma Gandhi of his age.
"His campaign for Catholic emancipation and his principled opposition to slavery was - and still is - admired around the world," he said.
"We are delighted to honour this towering figure in the city which formed the backdrop for much of his career."
Mr O'Connell lived at 14 Albermarle Street from February 1833 for up to six months, during a significant time for the groundbreaking 19th century politician.
During that year's general election, 39 of his supporters in the campaign against the Act of Union were elected to the House of Commons.
Laws to abolish slavery, in which O'Connell played a major role, were also enacted.
The plaque was unveiled at the house after O'Connell's descendants proposed the idea to a panel of judges at English Heritage.
At the official unveiling, Geoffrey O'Connell, his great-great-grandson, said they were delighted to see the commemoration in a city which did much to shape his beliefs and ideals.
"The 'prophet of a coming time' was how the future British prime minister William Gladstone described O'Connell and his peaceful struggle for universal rights for people of all races and creeds is as pertinent today as it was prescient then," he said.
A four-storey terraced house dating from the 18th century, the property has been converted into apartments and a retail outlet, squeezed between designer shops.
The size of the house and its desirable location is a reflection of O'Connell's stature at the time.
"I am anxious to make a good appearance in London for the sake of our girls," he said to his wife, Mary.
O'Connell's sons Maurice, Morgan and John and his son-in-law, Charles, also lived there.
Blue plaques are granted to historical figures who lived in London for a significant time and who are deemed eminent and exceptional in terms of their public and national recognition.
O'Connell regularly visited and lived in London after fleeing revolutionary France for the city in 1793 to study as a barrister.
After taking his parliamentary seat in 1830 as the first popularly elected Catholic MP since the Reformation, he sat in the Commons for the rest of his life and was a major force in Westminster.
Ireland's Diaspora Minister Jimmy Deenihan and Ireland's ambassador to Britain Dan Mulhall were among those at the unveiling.
The plaque's inscription includes O'Connell's popular sobriquet, The Liberator.
"I have been a lifelong admirer of my fellow Kerryman, Daniel O'Connell, and particularly his towering achievement in advancing through peaceful means the rights of the Irish people at a very difficult time in our history," said Mr Deenihan.
"O'Connell was not just an Irish figure, but a man of international stature, renowned for his progressive views, his belief in the universality of human rights and his unshakeable commitment to liberal, reforming principles."
Other Irish luminaries commemorated with an English Heritage blue plaque include Ernest Shackleton, Bram Stoker, Oscar Wilde and WB Yeats.