If they didn't own anything then why do their ancestors still own great chunks of places like the UK - where many members of the upper classes can trace their ancestries, and the lands they own, back to the Norman conquest?
Life as a royal in medieval times was pretty tough, but largely because they were still expected to fight to maintain their position, compared to the lifestyles of most people in the countries they ruled they were well fed, well clothed and had much better accommodation than most.
Both land and other stores of value (eg gold & silver) were frequently traded between medieval landowners.
Even looking at Europe alone, the Kinghts Templers acted as bankers as early as 1000AD, which allowed the rich to transfer money over distance. By the 1300's the Medici's had created an institution that would be recognizable as a modern bank.
For example, in medieval times in Europe (and identically in sub-saharan africa), there was very low inequity.
The ruling class did not own anything except the shirts off their backs. Their jewels were "crown jewels" and couldn't be sold. They had control of the land, but usually couldn't sell it between themselves.
The few fungible valuables they had (salt, and other trade goods) barely elevated them above the common masses.
Today, the power of the ruling class is magnified a 1000 fold, but the working bottom 10% lives better than they ever have thanks to innovations in technology. Indeed, the bottom 10% lives even better than medieval kings despite living in a highly unequitable society.