As a Medieval Count you are a very powerful person. In early-high medieval France and Germany (where the title was primarily used, Counts were essentially mini Kings in a very decentralised state. You minted your own money, had your own legal system, commanded an army of vassals and only obeyed orders from the king only if they suited your interest. As the 12th century progressed the Count of Anjou, Henry Plantagenet managed to gain around half of France (as a nominal allegiance to the French King) through a marriage, warfare and skilful political machinations. In 1154 he succeeded another French Count, Stephen of Blois to the throne of England after over a decade of dynastic war. With all these responsibilities as a count you’d want probably someone at least semi competent to succeed you, however........

The likelihood is that you don’t want to set a very dangerous precedent so you do nothing. Bare in mind that you believe your position in society is ordained by a great chain of being that stretches from the lowliest peasant up to almighty God. Your role as a noble is not simply a job which can be given to the best candidate.

If you are worried about your son’s competence you can surround him with good advisors and put people you trust in meaningful administrative positions to steer him in the right direction. However there were situations that complicated this. Henry II ruled England and Ireland as King and Normandy, Anjou, Aquitaine, Maine and Brittany (among other domains) as Count or Duke. He envisioned this as an arrangement only during his lifetime, after which his sons would inherit the various parts of his empire.

In theory Henry’s principal domain was England where he was King, so by custom this should have gone to his eldest surviving son. Henry however envisioned giving England to his favourite son John (number 3). Under this arrangement all of his children were to receive domains and noble titles but the realm he considered most important would have ended up in the hands of the son he considered most competent. This did not lead to a happy family life.

Henry also had numerous illegitimate sons, including Geoffrey who was one his father’s most trusted confidants. Henry considered Geoffrey to be his most skilled and loyal offspring, making him Bishop of Lincoln, Archbishop of York and eventually Lord Chancellor. We can speculate that Henry would have liked to make Geoffrey his heir, however this was unthinkable in the 1180s. On his deathbed King Henry allegedly paid Geoffrey (the only son present) one of history’s great backhanded compliments “my true born sons are the real bastards”.

The problem of what to do with an obviously incompetent person becoming King was one of the central issues of English politics in the 14th and 15th centuries, and popped up again in the 17th.

When monarchs were removed from the throne the act was justified appealing to divine favour being removed from the monarch, the monarch rendering themselves unworthy through misgovernment and the legitimacy of another candidate. King Henry VI, inherited the crown as a baby, likely suffered from some kind of severe learning difficulty, had a series of mental breakdowns, could not not remember long periods of his reign and did not exactly embody the ideal of medieval kingship. Henry was alleged to have spent the entire battle of St Albans singing to himself under a tree. Nonetheless serious efforts to depose him did not take place until an extended period of mental incapacity when it was widely believed his wife, Margaret of Anjou was ruling through him as a puppet.

Another example from this period across the English Channel is Charles VI of France (the mad). No one seriously questioned Charles’s right to rule even though he often didn’t know he was King, committed murder in mad rages, and ran wildly around the corridors of his palaces. His most famous delusion was that he was made of glass and he insisted iron rods were sewn into his clothes to prevent him from shattering.

Two centuries later during the English civil war, event the most radical supporters of the English parliament were reluctant in the extreme to countenance deposing the king. King Charles I was offered compromises almost up until his trial of execution. Oliver Cromwell who’d emerged as de facto Parliamentary leader believed that monarchy was a divinely ordained institution and was deeply troubled by the idea of killing a king. He even contemplated taking the throne himself on the justification that God could switch his favour to another royal candidate (as happened in the biblical story of David and Saul).

You can find numerous examples of this handwringing by European nobles even in more recent history. Two interesting cases come from the Hapsburg dynasty. Charles II of Spain, though mentally sound (it was discovered much to everyone’s surprise that he’d created detailed plans for his succession) struggled to walk (he learned age 4), had an overgrown lower jaw, struggled to speak (he learned age 8) and was likely physically unable to conceive children. No one seriously questioned his right to rule.

Ferdinand I of Austria (1793-1875), Charles’ distant relation suffered from many similar issues. He was epileptic, had a speech impediment, numerous neurological problems and learning difficulties as well as an enlarged head caused by Hydrocephalus. When he tried to consummate his marriage he had five seizures. Ferdinand’s father Francis II was desperate to rebuild Austria after the Napoleonic wars and wanted essentially to turn the clock back to before the French Revolution. By making another relation Emperor he would be going against his beliefs about the sanctity of his office and the divinely ordained chain of being. He was willing to uphold this even at expense of his son’s health and the potential damage to his Empire. During Ferdinand’s reign power was largely in the hands of his Chancellor, Metternich whom Francis appointed to guide his son and continue his conservative policies. Ferdinand was largely popular in Austria because of his happy demeanour but it was obvious where the real power lay. When the revolutions of 1848 erupted Ferdinand was closely associated with Metternich’s policies and was unable to plot a different course. He was eventually persuaded to abdicate in favour of his nephew and spent a largely happy retirement in Prague.

Even during the modern era it took revolutionaries banging at the gates for the Austrian royal family to accept that there might be a more suitable candidate for the throne. In today’s world where Monarchs and aristocrats generally don’t command much power this has largely become a non issue, but for centuries this class jumped through hoops to continue with a system they considered to be the divinely ordained order. It would be possible to write all day about unsuitable nobles who succeeded to or remained in office despite, extreme incompetence, serious mental/physical illness or extreme flaws of character.

Caveat: When we discuss the feudal system most historians are referring to practises which took place in the modern day countries of England, France, Germany and parts of Italy. Essentially the former Carolingian Empire plus England. Other places outside these areas such as Spain, Scandinavia and parts of Eastern Europe came to adopt many of its precepts over time.

Some societies on margins of Western Europe carried over their ancient kinship ideas into the medieval period. Outside pressure forced most of them to adapt to the norms of western Christian society, however it wasn’t uncommon to find peoples in medieval Europe who didn’t conform to the standard ‘eldest son gets it all’ form of noble inheritance. The Normans for example who were descended from Vikings settlers in northern France practised unofficial polygamy, a carryover from their ancestors. Duke William of Normandy’s father Robert kept multiple concubines whose offspring the Church considered illegitimate. Norman Dukes were this able to pick a favourite son to succeed them rather than the throne passing automatically to the eldest. The story of Henry II (William’s great grandson who wouldn’t leave the throne to his bastard) demonstrates how much values had shifted in a few generations.

Ironically a generation later the Normans were horrified when they found this practise in Wales, a land they tried and largely failed to conquer following their success in England. Welsh nobles generally kept several wives (once again not recognised by the Church) and would have a variety of sons to choose from when it came to inheritance. Unlike in medieval England illegitimacy was no barrier to noble rank. Welsh nobles were confused as to why the French and English aristocracy would risk their bloodlines dying out, or handing over their lands to a terrible son. Rhys ap Gruffydd, Prince of South Wales had at least nine sons eight daughters by different women although counting is difficult as he called at least three sons Maredudd and at least three daughters Gwenllian. King John would later marry his illegitimate daughter Joan to the Welsh Price Llewelyn knowing that it wouldn’t be judged in the same way a French noble would view an illegitimate bride.