Mary was widowed at just eighteen-years-old when her first husband, King Francois II of France died as the result of an abscess developing from an ear infection. In order to continue the Stuart dynasty she needed to remarry. Ultimately this led to arguments about the Crown Matrimonial – i.e. would her husband be allowed to rule if she died but in the short term there was the small matter of possible candidates for the job.
Don Carlos, son of Philip II of Spain had been mentioned whilst she was still in France. Aside from the fact that the young man was Philip’s heir there was also the issue of his mental health. Ultimately he would be locked up by his father and die in 1568 after six months in a small room on his own. Mary Queen of Scots uncle, the Cardinal of Lorraine was less concerned about the sanity of Don Carlos than the power that the marriage would give to Philip II.
Charles, Archduke of Austria was identified as a suitable heir but Mary wasn’t keen. Charles would go on to negotiate for Elizabeth I’s hand.
Elizabeth I helpfully suggested a match that she felt might work – Sir Robert Dudley, her master of horse and alleged lover – not to mention participant in yet another conspiracy theory i.e. the death
of his wife Amy Robsart in Abingdon in suspicious circumstances. Historians think that Amy had cancer but at the time her fall down some stairs looked rather a lot like the removal of one wife to make way for one with a crown. Elizabeth possibly thought that if Mary accepted Dudley that she could trust him to work in England’s interests or else she was being deliberately provocative. At any rate Dudley became the Earl of Leicester in a bid to be made to look more appealing.
And then there was Pierre de Chatelard or Chastelard. He was a young french poet. Essentially Pierre fell in love with the queen and she failed to spot that it wasn’t love of the courtly kind and consequentially encouraged him. This sounds slightly cruel but the concept of courtly love was that a man should express devotion to a woman beyond his reach – the whole thing reached new heights in the court of Elizabeth – think of Spencer’s Fairie Queen for example. In Scotland the misunderstanding between affectation of passion and passion itself went badly awry. Pierre hid in Mary’s bedroom at Holyrood. Fortunately he was discovered by Mary’s servants and booted out. He was told to leave Scotland.
Pierre agreed that it was probably best if he returned to France – except he didn’t. He followed Mary on a progress and at Rossend Castle, Pierre managed to get into her bedroom once more. On this occasion the queen was in situ and in a state of undress. Pierre accosted the queen and there was rather a lot of shouting and screaming, followed by the arrival of Lord Moray (James Stewart Mary’s illegitimate half-brother) who removed the offending frenchman, arresting him and locking him up in one of the castle’s dungeons.
Mary was so outraged by proceedings that she felt that de Chatelard should have been killed on the spot but Moray insisted that the poet be given a trial and executed in the market place at St Andrews which was where the court travelled from Rossend.
The National Portrait Gallery collection contains the above image which dates from 1830 depicting the lovelorn de Chatelard playing the lute for Mary.
In November 1558 Henri II of France upon hearing the news that Mary I of England (Bloody Mary) was dead declared that his young son, Francois, and his daughter-in-law, Mary Queen of Scots were king and queen of England by virtue of Mary Queen of Scots descent from Margaret Tudor, the eldest surviving daughter of Henry VII. In the eyes of the Catholic world Elizabeth was at best the illegitimate daughter of Henry VIII and Anne Boleyn and could thus have no claim to the crown. 
Barely two years later in December 1560 Francois died from an ear infection that turned into an abscess on his brain. Mary decided to return Scotland – landing her squarely on Elizabeth’s doorstep. This was a development that made her claim to the throne more dangerous not least because Mary refused to accept the Treaty of Edinburgh which recognised Elizabeth as Queen of England. As a direct consequence of her refusal to ratify the treaty Elizabeth refused to permit her cousin safe passage. Mary relied on God and good winds to get her home to Leith on August 19 1561 but the tone was set for growing animosity between the two queens until Mary went to her death at Fotheringhay in 1587.
At Calais, in French hands since 1558, Mary boarded the vessel that would take her back to a Scotland where John Knox preached Protestantism. The man who was the admiral of her little fleet was none other than James Hepburn, earl of Bothwell.