Charles II (29 May 1630 OS – 6 February 1685) was the King of England, Scotland, and Ireland.

Charles II's father King Charles I was executed at Whitehall on 30 January 1649, at the climax of the English Civil War. The English Parliament did not proclaim Charles II king at this time. Instead they passed a statute making such a proclamation unlawful. England entered the period known to history as the English Interregnum or the English Commonwealth and the country was a de facto republic, led by Oliver Cromwell. Scotland, however, was then a separate kingdom and the Parliament of Scotland proclaimed Charles II King of Scots on 5 February 1649 in Edinburgh. He was crowned King of Scots at Scone on 1 January 1651. Following his defeat by Cromwell at the Battle of Worcester on 3 September 1651, Charles fled to mainland Europe and spent the next nine years in exile in France, the United Provinces and the Spanish Netherlands.

A political crisis following the death of Cromwell in 1658 resulted in Charles being invited to return and assume the throne in what became known as the Restoration. Charles II arrived on English soil on 27 May 1660 and entered London on his 30th birthday, 29 May 1660. After 1660, all legal documents were dated as if Charles had succeeded his father in 1649. Charles was crowned King of England and Ireland at Westminster Abbey on 23 April 1661.
Charles's English parliament enacted anti-Puritan laws known as the Clarendon Code, designed to shore up the position of the re-established Church of England. Charles acquiesced to the Clarendon Code even though he himself favoured a policy of religious tolerance. The major foreign policy issue of Charles's early reign was the Second Anglo-Dutch War.

Great Plague and Fire

In 1665, Charles was faced with a great health crisis: the Great Plague of London. The death toll at one point reached a peak of 7000 in the week of 17 September. Charles, his family and court fled London in July to Salisbury; Parliament met in Oxford.Various attempts at containing the disease by London public health officials all fell in vain and the disease continued to spread rapidly.

Adding to London's woes, but marking the end of the plague, was what later became famously known as the Great Fire of London, which started on 2 September 1666. The fire consumed about 13,200 houses and 87 churches, including St. Paul's Cathedral. Charles, and his brother James, joined and directed the fire-fighting effort. The public blamed Roman Catholic conspirators for the fire, though it had actually started in a bakehouse in Pudding Lane.

(Extract based upon wikipedia entry)

In The Last Seal Charles II features in the story right at the end when Ben and the others meet him after the Fire, but much of the background to the story relates to the early years of his reign: the Dutch Wars, the Plague and the Fire particularly.