I can see some validity in your argument, John. But the problem, as I see it, is determining what is, and is not, ‘legitimate’ in this context. Some people regard the Israeli occupation of the West Bank as illegitimate. Where either of us stands on that issue is not relevant here, I use it as an example of the difficulty of defining legitimacy when it comes to land rights.
I am an English man living in Ireland, acutely aware of the fraught relationship between Great Britain and Ireland over many centuries. I am presently researching, and attempting to write a book about, the activities of a man who came to Ireland as part of a plan to secure the transfer of land and other assets, traditionally the property of the Church, to the Crown. It is important to add that this transfer also took place in England and Wales. His descendants still, to this day, occupy some of the land that was granted to him by Henry VIII and his successors (Edward VI, Mary, Elizabeth I).
My house is built on land which would once have been part of that estate. Under current Irish law I own it, house and land, outright.
But what happened in the years following the reformation was nothing more than another phase in the centuries old wars, across the whole of Europe and beyond, between the wealthy families who claimed ownership of various territories and continually sought to expand. Along the way the victorious king or duke would grant parcels of land to his most trusted lieutenants. The ordinary folk, the multitudes who made up the armies, remained as tenant farmers or labourers, paying their dues to whichever fortunate individual held the ‘Lordship’ for the time being, as well as to the Church.
I could use the reductio ad absurdum argument by asking this hypothetical question: if every person now living has a ‘natural’ right to the land he or she ‘owns’, and the population is continually increasing, where does that leave children born tomorrow, next week or next year?
Inheritance is one answer, but it can not account for that population increase. In any case, it only works equitably for the family of the curent owner if each pair of parents produces two children. My grand daughter is fortunate: both she and her father are without siblings. In families with multiple siblings there are often disputes about inheritance.
Returning to Irish history, this was one of the factors behind the Great Famine of the mid-nineteenth century. Land was continually being sub-divided between children as the population increased exponentially. Then, as now, emigration provided a part of the answer, incidentally contributing to the increase in the European population of North America.
I do not pretend to know how to deal with this conundrum. But I hope you can see why I am sceptical about the idea of a ‘natural right’ to property.