The trouble was that King Edward III had too many children. It wasn't just that, of course: there was also the tendency for heirs to predecease their fathers and for boy kings to succeed to the throne. Salic Law did not apply in England  but primogeniture certainly did, although it seems no one knew quite how to interpret it. The lawyers should have had a field day but the rulers of England were martial men  and had a number of other sorts of field days.

Edward's heir - Edward, the Black Prince - predeceased his father and the crown passed to his son, Richard II, a boy of ten. Boys of ten surely do not make able monarchs and this proved to be the case with Richard. Richard also did not produce an heir although the did designate one - and this is where we start to get complicated.

Edward III's second surviving son (there was a boy in between, who did not survive infancy) was Lionel of Antwerp, Duke of Clarence who again predeceased his father. He did however produce an heir but this was a daughter called Philippa, who married Edmund Mortimer, Third Earl of March, a member of a powerful dynasty. They had a son Roger Mortimer, Fourth Earl of March, and this was the person whom Richard II designated his heir. Unfortunately Roger predeceased Richard but did father four children, two of whom Edmund Mortimer, Fifth Earl of March and Anne Mortimer, the latter, who died at twenty, made a marriage which was to bring a disaster to England. We'll come to that later.

The third surviving son, John of Gaunt, First Duke of Lancaster, thrice married and father of many children, including a quartet of illegitimate ones (the Beauforts, later legitimized but they and their descendents were excluded from the throne), many of whom played a part in what was to follow. And, to be complete, an illegitimate daughter, who didn't. Here, for now, we are interested in just one son - Henry of Bolingbroke. Richard II, becoming increasingly vindictive and even paranoid, exiled Bolingbroke and to rub salt into the wounds confiscated John of Gaunt's estate on the latter's death, so disinheriting Bolingbroke. Bolingbroke then invaded England initially announcing this was to claim his Lancastrian inheritance but then to claim the throne: Richard was forced to abdicate and died, probably murdered, shortly afterwards. Bolingbroke became king as Henry IV, the first of the Lancastrian kings; his reign was not a happy one being plagued with rebellions but his son succeeded to the throne as Henry V. Although Henry IV had taken the throne by force, it could be said that he was the legitimate heir, although others thought differently.

Now we come to the man whose tomb we see here - Edmund of Langley, First Duke of York - the fourth surviving son of Edward III. He had a daughter and two sons: Richard of Conisburgh, Third Earl of Cambridge and the elder Edward of Norwich, Second Duke of York,  both of whom we'll come to shortly.

The next, fifth and last surviving son (there were two children who died in infancy after Edmund of Langley) was Thomas of Woodstock, First Duke of Gloucester. He can be quickly dealt with: his nephew Richard II had him murdered at Calais.

Now we come to the marriage which brought disaster we have alluded to above: Richard, Earl of Cambridge married Anne Mortimer and they had a son another Richard.

Henry V decided to invade France continuing the Hundred Years' War, which seemed to have gone quiet, but before he left he had to deal with the Southampton Plot: this was an attempt by Richard, Earl of Cambridge and others to replace Henry as king by Edmund Mortimer, Fifth Earl of March , who was Richard's brother-in-law, both of whom we have alluded to above. However it seems that Edmund Mortimer didn't want to be king at all - or perhaps he got cold feet - and he revealed the plot to King Henry. The Earl of Cambridge and the other plotters were executed for treason. Edward, Second Duke of York appeared to have nothing to do with his brother's plot and he sailed to France with King Henry only to be killed at Agincourt. This Duke of York had no children and his title passed to his executed brother's son, Richard, Third Duke of York.

And then it happened again: Henry V died young and was succeeded  by his son Henry VI . This latter Henry thus became king not only of England but shortly afterwards, on the death of the French King (Charles VI), king of France as well, or at least a good bit of it. This was because of his father's French conquests, helped by the concurrent civil war in France and according to the Treaty of Troyes.  Unfortunately Henry VI was six months old and if children do not make able monarchs, babies certainly do not and Henry was about to prove it in due course.

After several years of ineffective rule during which the English holdings in France were lost, Richard, Third Duke of York, alluded to above, made a bid for the English throne, the French ones having by now been lost. His claim was that he was descended from Edward III's second surviving son, albeit twice through female descent and a generation more than that of Henry VI who was descended from the third surviving son and though all male lineage. However Richard was also descended from the fourth surviving son entirely through male descent and one generation less than Henry VI. Who had the better claim: I've no idea and it seems neither did they - so they decided to fight it out. Henry VI - neither a effective king nor soldier - was championed by his wife Margaret of Anjou and the so-called War of the Roses began.

Richard, Duke of York failed in his bit for the throne as he was executed after the Battle of Wakefield. However he had a son, Edward who became king as Edward IV and who died young leaving a young boy as heir....