Leaving Oxford without a degree, Holtby proceeded to the English College at DouaI where he arrived by way of Antwerp, in August 1577, and was received into the Roman Catholic Church.
The college was relocated to Reims, where Holtby continued his theological studies until February 1579, when he was sent on the English mission.
[3] In 1581, Father Edmund Campion paid him a visit, and while staying in his house composed the famous Decem Rationes and urged him to join the Society of Jesus.
Richard entered the Society of Jesus in 1583 and crossed the English Channel to participate in his Spiritual Exercises with Father Thomas Derbyshire.
After the execution of Father Henry Garnett he was appointed superior or vice-prefect of the English mission, and during his three years’ tenure of that office he appears to have resided in London.
A government spy in a report to the privy council in 1593 describes him as "a little man, with a reddish bearde", and adds that he chiefly resided at Mr. Trollope's house at Thornley, co. Durham.
In order to evade arrest he assumed the aliases of Andrew Ducket, Robert North, and Richard Fetherston.
"Of no other English Jesuit", remarks Dr. Jessopp, "can it be said that he exercised his vocation in England for upwards of fifty years, and that, too, with extraordinary effect and ceaseless activity, without once being thrown into gaol or once falling into the hands of pursuivants; and quietly died in his bed in extreme old age."