Well, again, I Claudius was an imaginative take - grounded in an intelligent (but not necessarily completely accurate) interrogation and interpretation of some historical sources and intelligently re-imagined for a twentieth century audience.
Re 'Mid Evil' (that is a joke, right?) history - Medieval - history, while G R R Martin happily admits that the Wars of the Roses served to some degree as affording inspiration for Game of Thrones, Game of Thrones (while superb reading material, - I haven't seen any of the TV series - and again, an intelligent treatment of some historical source material), is not medieval history.
Trade, religion, politics, pestilence and cities also influenced outcomes every bit as much as war.
Re morals, ethics, and free will, I believe that there is a choice - a form of free will - in such matters. Whether one acts upon desires, or needs (and not only sexual) is a matter of choice.
One does not need to act on an impulse, or desire, or feeling; one decides too so, or allows oneself to do so, or chooses to do so.
Now, that choice can be influenced by other matters, societal traditions, constraints, opportunity, the degree to which one believes oneself bound or beholden to systems of belief and the degree to which one chooses to live an ethical existence.
One may be influenced or prodded by one's desires; one is not compelled to act upon them, and, if to do so is in contravention of norms, or ethics, or laws, or morals, one does so because one has given oneself permission (or excuses) to do so, and opportunities have arisen which allow one to disregard constraints - including consequences - which might more usually exist in one's usual environment.
Unaccountable power leads to unconscionable abuses in every system, be it economic, financial, political, sexual, religious, precisely because the rewards of power are so great.
There are answers to that - and they tend to fall on what we might term the 'liberal' or 'progressive' - spectrum: More education, a society comprised of citizens not serfs, cities, the concept of the public good and the public space to be promoted in policy, public policy and the exercise of political power with the public good in mind; more accountability, which comes from institutions that are respected and independent - so that power follows the institution rather than the individual - fewer divisions and degrees in wealth between the richest and poorest percentiles in society, social mobility, a significant degree of economic activity where the citizenry feel that they have a stake in the system, sufficient government regulation where needed (in areas where only regulation can ensure the public good, health, education, some housing, state security), especially in areas which may themselves lie outside of the orbit of regulation. And so on….
As for incest, Caligula was one thing, - deranged to the end - but most cases that I have read about fall under the heading of grotesque abuse, an abuse of power and an imbalance of power that is more insidious for being harder to report, with relatives reluctant to accept what may have happened.
