I probably agree there is no essential list. However, I think we all agree or most do that there are essentials to a liberal education which includes a heavy dose of various social sciences, humanities, and arts along with some exposure to math and physical science. There are essential skills that go along with the above, like how to read, write, and study, how to work on notes, concepts, and how to understand some of the issues of a field. It takes considerable skill to organize even one semmester of this kind of work and make it a somewhat coherent body that the students get to take with them.
There is a central construction that is essential to something like art history. It has to have a chronology, so the time lines form a basic architecture, about which to hang the art. You don't have to believe there was progress, or that societies went through specific periods, or believe there is such a thing as good art, but you do have to form that chronological sequence to make sense of the changes over time.
I can't remember how many art history books I read, but the one I kept was Jansen's The History of Art. My current copy is almost separated from its thirty year old binding. There have been newer additions, and spin offs, which I would have to go over to check. Probably all added something to the core narrative. This standard core, needs a lot of reworking from a Marxist informed social history of the same periods, in order to hang the art in its society. (Arnold Hauser helps some) Another central context is the role of Christianity and its dialogue with the secular world over time. So as a surprize it turns out that theology and philosophy carry on the mysterious dialogues of their own within the art production social-technical systems. As an example, there was a critical role played by the development of perspective, that materialized space as in the phrase form in space. Such construction didn't exist before the early Renaissance or very late Gothic (except in middle period Greece and Rome) and then re-emerged in studies of Brunelleschi. He and his boyfriend Donatello who went to Rome and studied Roman ruins specifically to systematize perspective and proportion.
Nearly contemporary was Durer. Try to contemplate Durer's Meloncolia, the angel of reason despares his tools of spatial rendering, his reason, his child of inspiration are gone, or lost to him. The sun is setting on his age... I hate to see that evening sun go down (Bessie Smith's great line to open St. Louie Woman...)
Donatello freed sculpture from its wall relief format, to free standing human bodies of great materiality--and spiritual power--so sculpture could stand on its own. B's architecture created that sense of a `humanistic' scaled architecture...(lots more detail goes here which is relevant to a liberal arts education, one in pictures and not words.)
These apparently simple ideas require basically another lifetime of work.
Each country has a national narrative of their arts and their history...their language canon lays at the core. In a sense it doesn't matter if the general outline or the detail are true in any objective sense. What matters is what their population believes. Does it have a basic fidelity to a sequence of events? What changed after the mid-1970s was the loss of that fidelity.
As I discovered in the aftermath of the 1960s, almost every period re-writes history both recent and past.
CG