Up until now, the possibility of having a group of people who lead a leisure life without an undercaste of slaves hasn't existed. Automation is a new thing under the sun.
Stop believing all this 'robots are coming for our jobs' crap. The robots have always been here.
There is plenty of work. An astonishing amount of work is available for people to do that isn't being done, and it's not because people are obsolete. What is lacking is capital directed at hiring people for that work. You can argue about why this is, but the basic reason to me is the general lack of demand because, more or less, the rich have all the money.
Here is Krugman on the subject: http://www.nybooks.com/articles/2015/12/17/robert-reich-chal...
A monarch of the past would have obviously better access to food, more of it, higher quality, they might have slightly less variety available (dependent on the era and location) but they certainly weren't eating the prepackaged garbage that passes for low budget food today.
By law they owned not only their own vast properties, houses, palaces, etc. but also that of all of their subjects and nobility allowing them to give and take as they wished from anyone under their dominion. Even after reforms almost all royal families were still left with vast holdings that produce more than enough wealth to live absurdly opulent lifestyles. There have been many cases of indebted rulers but that is debt in the sense of illiquidity, they were still asset rich and able to melt the plate down to pay off the debts, so to speak.
This notion that everyone was universally worse off in the past and therefore even the lowest of the modern low are somehow better off in their current state and should be thankful for it is the crudest of fallacies. The trite example of modern healthcare being a shining example of why it's better to be poor today than wealthy 200 years ago is equally absurd considering that such care is often avoided by the poorest due to its cost right up until it's too late to do anything about it. You wind up with a situation where a person's only choice is to hope not to get sick since they can't afford the treatment or the missed work either of which could put them even further under water or on the street.
Indeed, just the existence of cheap antibiotics are likely to make the most humble of today's citizens live decades longer than anyone from the past.
I'm going to guess none unless you forget your toothbrush or some other small item. The estate of a king is essentially a hotel room that he also happens to own along with dozens or hundreds of other such locations scattered around the country he rules. Little inventory would be kept there since the majority of day to day furnishing, and I do mean furnishings as including pieces of furniture, would travel with the court as they moved from estate to estate. Nothing valuable would be left behind for the same reasons that you wouldn't leave your laptop at the hotel after you check out, chances are when you come back (if you come back) it's not going to be there and if it is there's a good chance someone else will have had their grubby paws all over it the entire time you were away.
After looking up the inventory in question, it also happens to contain enough livestock and grain to feed well over a 100 people (there were about 100 full time residents) as well as a list of buildings including the mansio itself, two smaller manors, 17 wooden houses, 3 barns, a stable, a kitchen, a mill, two gardens, and a granary. There were also more than 60 horses boarded there.
As for kings not living as long as modern paupers, Charlemagne was a septuagenarian when he died.