De Souza was born in Assagaum, Goa, to a Roman Catholic family belonging to the Saraswat Brahman community.
He was the tenth descendant of Roulu Camotin who had converted to Catholicism at the point of the sword in 1537, adopting Diego de Souza as his name at his baptism.
Principal John Harward of Royal College encouraged de Souza's passion for history and English literature.
[4] De Souza was expected to be called to the Bar in the family tradition, but he fell out with his uncle and made his own way in life.
In 1914 De Souza was indicted for writing an editorial entitled "Justice at Nuwara Eliya" that suggested that Thomas Arthur Hodson was sympathetic to the views of the constabulary when he tried cases as District Judge and Police Magistrate.
Bawa before a three-judge panel of the Supreme Court (Renton, Pereira and De Sampayo) that sentenced him to one month imprisonment, reportedly without a proper hearing.
His obituary in the Ceylon Morning Leader on 18 May 1921 read: The news of Mr Armand de Souza's death came as a great shock, for I had not even known he was ill.
In his paper, by far the most widely read, he was constantly cheery and brave, and did more to keep up the spirits of Ceylon during that time than any one man, to my mind.
I found him straight, and he was my friend.He was father of Senator Doric de Souza of the LSSP (the Lanka Sama Samaja Party, Sri Lanka's Trotskyist party) and Torismund de Souza, Editor of the Times, as well as Aleric and Lena who both died young.
Australian composer Dr Gina Ismene Chitty is a granddaughter and Actress Fabianne Therese is his great-great-granddaughter.