Henry VI was the son of
King Henry V of
England, and succeeded to the
throne in
1422 at the age of eight months (supposedly presiding over
Parliament from his mother's lap) after his father's death. He was officially crowned king of England just before he turned 8, and two years later also crowned king of
France due to the treaty Henry V had gotten the French to sign. However, his English regent died and French nationalist movements such as that led by
Joan of Arc ate away at English control of France until in
1453 only the city of
Calais was really in English hands.
Henry VI suffered from periods of insanity (just like his grandfather, Charles VI of France) and during these times his cousin Richard the Duke of York took charge. Henry married a determined woman, Margaret of Anjou and had a son, Edward. When Henry was not having obvious mental problems, Margaret and Edmund, Duke of Somerset, were the powers behind the throne. These two were on the side of the House of Lancaster, whose emblem was supposedly the red rose; the Duke of York's emblem was the white rose, and hence the fighting between these two sides which broke out by 1455 is known as the Wars of the Roses. (NinjaPenguin tells me that "The War of the Roses was actually a misinformed title; the red rose was actually a symbol for the Tudors, not the house of Lancaster. The name was given by Longfellow, but I since learned that it
isn't too accurate.")
In 1460 Henry was captured by Yorkists and forced to make the Duke of York heir to the throne rather than his own son. Queen Margaret led the Lancaster forces and freed her husband in February 1461, but a month later the Yorkists defeated the Lancasterians and put the son of the now-late Richard, Edward the Duke of York, onto the throne of England as Edward IV. Henry and Margaret fled to Scotland.
In 1464, Henry and company returned to England and tried to force a coup d'etat, but failed and Henry was imprisoned for six years. In October 1470 the Earl of Warwick managed to engineer a real coup and put Henry back on the throne, with Edward fleeing to Burgundy. Edward came back to England the next April and regained the throne. Henry was reimprisoned and died "from pure displeasure and melancholy" in 21 May 1471, while his son Edward was killed at the Lancastrian defeat at the battle of Tewkesbury. (Quote from David Williamson's The Kings and Queens of England; it's in quotes there but he doesn't give the source.)