Despite the birth of Mary's son James who was born on 19 June 1566 in Edinburgh Castle, the relationship between Mary and Darnley deteriorated over the next year. The young Darnley spent the evenings out drinking and womanising.
However, Darnley had become unwell – perhaps with smallpox - and on the night of 9 February 1567, stayed in the Provost’s lodgings at Kirk o’ Field in Edinburgh.
Mary had visited Darnley on the day of his death, but left to attend a masque in Holyrood.
At two o’clock in the morning there was a massive explosion at Kirk o’ Field.
Darnley’s body was found in a neighbouring garden the next morning, beside that of a servant’s. It seemed that they had run from the house in their nightwear and in terror.
It appeared that he had been strangled. The Queen’s husband had been murdered. He was 21 years old.