Short answers, pulled from the story.
The painting dates to circa 1532 or 1533 when Cromwell served as Master of the Jewel House. This work was created during his peak power years between 1532 and 1540 while he acted on behalf of Henry VIII.
Historians assume the original oil on oak panel was destroyed shortly after Cromwell's execution by beheading on the 28th of July 1540 in the Tower of London. Beckingsale published research in 1978 confirming the likely destruction timeline following his arrest at Traitors Gate on the 1st of June 1540.
Three versions survive held by the Frick Collection New York, the National Portrait Gallery in London, and the Chichester Constable collection in Yorkshire England. The Frick version hangs opposite Holbein's Portrait of Thomas More and underwent extensive technical analysis in 1952.
The sitter is Thomas Cromwell who sat for the work when he was around 48 years old. Historian R. B. Merriman described him as short stoutly built with a large face smooth shaven close cropped hair heavy double chin small cruel mouth extraordinary long upper lip gray eyes set closely together moving restlessly under light eyebrows.
Cromwell was a devout man keen to display this devotional book within his portrait as a symbolic reference to his religious devotion. Researchers discovered Cromwell's actual Book of Hours in the Wren Library at Trinity College Cambridge in 2023 after it was donated by Anne Sadleir.