Short answers, pulled from the story.
James Hepburn was the third husband of Mary, Queen of Scots, born around 1534 as the son of Patrick Hepburn, 3rd Earl of Bothwell. He was publicly accused of murdering Lord Darnley in 1567 but was acquitted at trial. He died in April 1578, having spent his final years chained in Dragsholm Castle in Denmark.
Bothwell was publicly accused and formally tried for the murder. The explosion at Kirk o' Field on the 9th of February 1567 killed Darnley and his aide, and Bothwell had carried gunpowder to the site with three accomplices named Dalgliesh, Powrie, and Wilson. The trial, opened on the 12th of April 1567 and running from noon to seven in the evening, returned a not-guilty verdict, though the accusation followed Bothwell for the rest of his life.
The circumstances of the marriage remain disputed. On the 24th of April 1567, Bothwell appeared on the road from Linlithgow Palace to Edinburgh with 800 men, told Mary that danger awaited her in Edinburgh, and escorted her to Dunbar Castle. Later accounts describe her as a prisoner there who was raped by Bothwell to force her consent, though whether she was a willing participant or an unwilling victim is a matter of genuine historical debate.
Anna Throndsen was a Norwegian noblewoman whose father, Kristoffer Trondson, served as Danish Royal Consul. Bothwell met her in Copenhagen around 1559, became engaged or possibly married to her under Norwegian law, then left her in Flanders after she had sold her possessions to support him. When Bothwell later fled to Bergen, Anna's cousin Erik Rosenkrantz had him remanded to Bergenhus Fortress while she brought a legal suit against him for abandonment and the return of her dowry.
After the confrontation at Carberry Hill on the 15th of June 1567, Bothwell sailed to Shetland, fought a three-hour sea battle off the Port of Unst, and was caught at Høyevarde lighthouse in Karmsundet off the Norwegian coast without proper papers. He was held in Bergen, where Anna Throndsen's cousin had him imprisoned, then transferred through Copenhagen to Malmøhus Castle and finally to Dragsholm Castle in Denmark, where he died in April 1578.
Bothwell was buried in a vault at Fårevejle church near Dragsholm Castle in Denmark. In 1858, the body was exhumed and found in a dried, preserved state, becoming known as 'Bothwell's mummy.' His extended family sought to have the remains returned to Scotland, but the request was refused, and the identity of the mummified body has never been conclusively established.