Short answers, pulled from the story.
Henry Stuart Lord Darnley was born in 1546 at Temple Newsam in Yorkshire. His father Matthew Stewart 4th Earl of Lennox had been stripped of his Scottish titles for treason in 1545 which forced the family into exile in England for two decades.
The marriage between Henry Stuart Lord Darnley and Mary Queen of Scots proceeded on the 29th of July 1565 in a private chapel at Holyrood. Mary had known him since 1560 and was immediately captivated by his appearance when he presented himself to her at Wemyss Castle on the 17th of February 1565.
Henry Stuart Lord Darnley and a group of Protestant nobles including the Earl of Morton and Lord Ruthven murdered Mary Queen of Scots private secretary David Rizzio on the 9th of March 1566. Rizzio was stabbed 57 times in front of the pregnant queen in an act intended to force Mary to grant Darnley the Crown Matrimonial.
Henry Stuart Lord Darnley died on the night of the 9th to the 10th of February 1567 when two explosions rocked the foundation of Kirk o Field in Edinburgh. His body was found outside dressed only in his nightshirt suggesting he had fled his bedchamber in a panic before the blast.
The vault at Holyrood Abbey where Henry Stuart Lord Darnley was buried was opened by mobs in 1668 and his skull was stolen between 1776 and 1778. Research in 2016 suggested that a skull held in the Royal College of Surgeons museum might be his but the truth remains elusive.