Max Nelson at The Paris Review:
To say that imprisonment helped Wilde develop that tone would be to make the same mistake that Wilde himself made about Wilfred Blunt. Certain passages in De Profundisdo seem to credit prison with strengthening and deepening their author’s nature, but only to the extent that, by subjecting him to intolerable, constant, and thoroughgoing misery, it gave him something against which to muster all his creative energies and all his verbal powers. “The important thing,” he writes himself telling Douglas at one of the letter’s turning points, “the thing that lies before me, the thing that I have to do, or be for the brief remainder of my days one maimed, marred and incomplete, is to absorb into my nature all that has been done to me, to make it part of me, to accept it without complaint, fear or reluctance.”
Wilde wrote De Profundis between January and March of 1897, near the end of his internment in Reading prison. His health had improved slightly since his early time in Pentonville, where he suffered miserably from dysentery and malnutrition. Sentenced to hard labor but ruled too weak for truly back-breaking work, he’d initially been ordered to pick oakum—a mind-numbing job involving the unraveling of rope into strands—alone in his cell. After his transfer to Reading, he was put in charge of distributing books from the prison’s limited library. When he eventually won the right to compose a letter in his cell, it was with the stipulation that each day’s pages be collected at nightfall.
more here.