I've picked up Shakespeare's Henriad that spans between Richard II's reign, right through the Wars of Roses, and it really seems to hammer home the importance of lineage and familial history in the Medieval England. Yorkists fought on the basis of Richard's deposition; Henry IV launched an invasion of France partly on the claim Edward III exercised, who himself did so because of his Plantagenet lineage. It's this rabbit hole of these intergenerational familial affairs, but the monarchs themselves might have only lived to 30 or so. A lot of the focus in these plays is on how the events of one monarch stand in relation to prior monarchs, but how much did England (or any Medieval nation) and people's everyday lives change between each reign? It's easy to see how fast technology & politics advanced and shaped the major historical movements between centuries in the modern era, but what would have changed between 1300-1400, or 1400-1500? Would there have been a noticeable difference in how wars were fought, or a difference in the internal political dynamics?
Whilst dynastic politics was very important in the Middle Ages it is important to realise that it was not unique to the medieval period and in England’s case continued into the 18th Century. However, whilst this changed little across the period, there were some pretty significant differences between different parts of the medieval period in terms of how wars were fought. For example, knights’ equipment changed drastically.
By the start of the 1400s, plate armour had become so good in quality that the shield began to fall out of fashion for foot knights, favouring a two handed weapon like a poleaxe or great sword. This was because well armorer men at arms had become more or less impervious to longbow arrows and doing away with shields allowed them to use heavier two handed weapons which had more reach and were often better at defeating armour. Perhaps the biggest change here is probably between 1400 and 1500 though, with knights beginning to fall out of practicality in the latter half of the century. It was beginning to become evident, especially in France, Spain and the HRE, that the armoured heavy cavalry which had been the trump card of European armies for so long was slowly falling out of practicality due to the increased use of pike and shot tactics. A sparsely armoured musketeer with a week’s training could kill a knight who had trained their whole life, and had costed masses of money to equip with armour and a horse. Also, the formidable charges which had made mounted knights so deadly was being made difficult to achieve due to the pairing of these musketeers with dense formations of pikemen who could repel such charges.
Furthermore, the way castles were being built was also changing significantly in the late 15th and early 16th Centuries in that they now had to be able to withstand artillery. For example, the star fort started to become more common in Europe since it was far better at dealing with this than archetypical medieval castles with curtain walls were.