Short answers, pulled from the story.
James Hepburn, 4th Earl of Bothwell, was the son of Patrick Hepburn, 3rd Earl of Bothwell, and Agnes Sinclair. He inherited the Earldom of Bothwell and Lord Hailes immediately after his father died in 1556.
He died in April 1578 after decades of confinement within Dragsholm Castle. His body was buried in a vault at Fårevejle church near the castle.
He died in April 1578 following years of imprisonment in appalling conditions at Dragsholm Castle west of Copenhagen. A pillar to which he was chained for the last ten years of his life can still be seen today.
After fleeing the confrontation at Carberry Hill on the 15th of June 1567, he fled to Norway where he was caught off the coast at Høyevarde lighthouse. King Frederick II decided to take him into custody in Denmark instead of releasing him to Scotland.
The Duke was sent to Copenhagen where the Danish monarch deliberated on his fate and ordered his transfer to Malmøhus Castle before sending him to Dragsholm Castle. He remained imprisoned there until his death because Mary never again would become Queen without political support.