Normally considered to be one of William Shakespeare’s history plays, King Richard III may have been intended as a tragedy, and is second only to Hamlet in its length. It’s likely to have been written in 1592-93, a period when London theatres were closed because of an epidemic of plague. It has proved one of his most enduringly popular history plays, attracting many stars for its lead role, and has been popular with painters too.
The real King Richard III of England (1452-1485) reigned for only two years, from 1483 to his death in 1485 at the age of thirty-two, a point generally taken as marking the end of the Middle Ages in England. In spite of the brevity of his reign, it saw two major rebellions, the second resulting in the Battle of Bosworth Field, where Richard was defeated and killed. He was the last English monarch to die in battle.
Richard, as the Duke of Gloucester, is plotting the downfall of his older brothers King Edward IV and George, Duke of Clarence. He turns the King against Clarence, who is then imprisoned in the Tower of London. He next tries to woo Lady Anne Neville, admitting to her that he killed Henry VI and his son, Anne’s husband.

Edwin Austin Abbey’s painting of Richard III of England and the Lady Anne from 1890 shows Richard while still the Duke of Gloucester disrupting Anne’s mourning of the murdered king and her husband.
Lady Anne reluctantly gives in to his advances. With the illness of King Edward, Richard is expected to become Prince Edward’s protector. Richard sends two murderers to kill Clarence in the Tower.
Clarence has a nightmare in which Gloucester pushes him overboard, causing him to drown. He is woken up by the two murderers, who kill him.

This etching and engraving of Henry Corbould’s original painting shows The Duke of Clarence Asleep in the Tower, as Brackenbury Leaves (1825-40). Brackenbury was in charge of the Tower.

William Blake engraved Thomas Stothard’s painting of Clarence’s Dream, from 1774. It doesn’t appear to refer to drowning, though.

Henry Fuseli shows well The Two Murderers of the Duke of Clarence in his painting from 1780-82.
King Edward hears of Clarence’s death, but thinks that he had cancelled his death warrant. The news puts the Duchess of York and Queen Elizabeth into grief, and fear for the safety of King Edward’s children. The Queen then hears of the imprisonment of her brother and one of her young sons from her previous marriage, so takes her younger son, the Duke of York, and her mother-in-law to sanctuary.

John Opie’s undated painting of The Duke of York Resigned by the Queen shows the Queen trying to protect her younger son from being taken to the Tower of London.
Prince Edward, the King’s eldest son, is brought to London, and the Duke of York is brought from sanctuary. These two young princes are persuaded to stay in the Tower. Gloucester’s plot to take the throne is gathering support. The Queen’s brother and one of her sons are to be executed at Pomfret, and the Lord Chamberlain and nobles travel to London. Gloucester and Buckingham, one of his supporters, move for the Lord Chamberlain’s summary execution, which was already intended before he was even accused of any crime.
Buckingham urges Gloucester to accept an invitation to become king, which Richard at first pretends to refuse, before accepting.

Paul Delaroche’s Edward V, Child King of England, and Richard, the Duke of York, his Younger Brother (the Children of Edward) from 1830 shows the two boys huddled together on a bed. Edward is staring wistfully into the distance, his head cocked on one side, knowing too well the fate that awaits them both. His younger brother has an illustrated book open on Edward’s thigh, but is looking anxiously, his brow knitted, to the left, as if he can hear someone approaching and their fate drawing close. At the foot of the bed is a small dog, also looking into the dark beyond.
The Queen is refused access to the two young princes in the Tower. She sends her remaining son overseas for his safety, and Lady Anne Neville laments her future as Queen to Gloucester, who is soon to be crowned King Richard.
With the new King Richard on his throne, Buckingham at first refuses to agree to the young princes being killed, then relents to the King, who refuses to give him the earldom of Hereford as promised. Buckingham flees to Wales, as Richard hires an assassin to kill the princes. Nobles start a revolt against the King, who tries wooing Elizabeth of York to prevent his rival Richmond from marrying her.
The remaining women of the court curse the King, who tries to force the Queen to woo Elizabeth on his behalf. Richard then hears of Richmond’s arrival at Milford Haven, and growing revolt among the nobles. Buckingham is captured and executed as Richmond and his army march towards Leicester.
The King sets his tent in Bosworth Field, and he and Richmond prepare to do battle there the following day.
In his dreams that night, Richard is visited by the ghosts of those he has had murdered: King Henry VI, Prince Edward, Clarence, Elizabeth’s brother and son, the two young princes in the Tower, Lady Anne, Buckingham, and others. They each curse him and wish victory to Richmond. The King wakes with a start in the morning, realising that he is about to die.

In this engraving after Henry Fuseli’s painting of The Ghosts Vanish from 1805, Richard is awakening as the ghosts of his nightmare are dispersing.

That may have inspired William Blake to paint Richard III and the Ghosts the following year. The two princes in the Tower float at the King’s feet, pointing up at him accusingly.

William Hogarth’s portrait of David Garrick as Richard III from about 1745 shows him waking with a start following his dream. Garrick (1717-1779) was the leading British actor and theatrical manager of the eighteenth century, and first played the role of Richard III in 1741.

William Hamilton’s painting of John Philip Kemble as Richard III from about 1787 also shows the King’s moment of waking. Kemble (1757-1823) was a leading actor of the day, and became manager of the Theatre Royal in Drury Lane, London, the following year.

That same year, the leading Danish painter of the day, Nicolai Abildgaard, painted this dramatic portrait of Richard III (1787) waking from his nightmare.
King Richard rallies his soldiers with a speech, and battle is joined.

Nathaniel Dance-Holland’s portrait of David Garrick (1717–1779) as Richard III from 1771 shows him fighting at Bosworth Field. By this late stage in his career, Garrick was still playing some major roles while devoting most of his time to managing the Theatre Royal in Drury Lane.
King Richard’s horse is killed, but he continues fighting until Richmond takes him on alone, defeats and kills Richard. Richmond is handed the crown and declares an amnesty to reunite England, which he seals by marrying Elizabeth, so uniting the warring houses of Lancaster and York.
References
Wikipedia on Shakespeare’s play.
Full text at Project Gutenberg.
Michael Dobson and Stanley Wells (eds) (2015) The Oxford Companion to Shakespeare, 2nd edn, Oxford UP. ISBN 978 0 19 870873 5.