As best we know, it wasn't. We have references to land ownership in ancient times from sources outside Europe. The Bible, in the Old Testament, discusses land ownership. There's evidence of private land ownership in Ancient Egypt. To quote from a review on the economic history website eh.net:

Baer (1962: 25-26) notes that “private individuals could own farm land at all periods of ancient Egyptian history,” and the “acquisition of fields for private purposes is … mentioned, from the earliest periods.” In the mid-third millennium, the mother of the entrepreneur/official Metjen conveyed her estate by means of an amat-per “house document.”

Similarly there is evidence of land property rights in Ancient China:

It is fair to state that private landholding property rights, including free-holding (dominant in North China over the long run) and lease-holding (paralleled with freeholding in South China during the post-Southern Song, i.e. 1279–1840) in imperial China laid the very corner stone of the empire’s economy since the Qin unification. Chinese laws clearly defined and protected such rights. In return, the imperial state had the mandate to tax the population of whom the vast majority (some 80 percent of the total population) were peasants.

And in Ancient India:

The evidence suggests that India developed a sophisticated concept of landed property from earliest history, with conceptual tools and legal instruments to define the rights of owners vis-à-vis rulers, rival claimants, and holders of subordinate interests

The idea that private land ownership is a new invention, particular to some time and place, appears to have come from 18th and 19th century ideas that there was a distinctive economic and political system called "feudalism", which then transitioned into "capitalism"(though the term "capitalism" only dates to the mid-19th century), which then caused a major surge in economic productivity, thus the Industrial Revolution. This theory's fame was boosted by Karl Marx.

But economic historians of the 20th history have failed to find any major institutional change in the English economy in the centuries before the Industrial Revolution. To quote the economic historian Gregory Clark:

The more we learn about medieval England, the more careful and reflective the scholarship gets, the more prosaic does medieval economic life seem. The story of the medieval economy in some ways seems to be that there is no story. Back in the bad old days, when the scholarship was less careful, the medieval economy was mysterious and exciting. Marxists, neo-Malthusians, Chayanovians, and other exotics debated vigorously their pet theories of a pre-capitalist economic world in a wild speculative romp. But little by little, as the archives have been systematically explored, and the hypotheses subject to more rigorous examination, medieval economic historians have been retreating from their exotic Eden back to a mundane world alarmingly like our own.

So land ownership wasn't invented in Europe, so it wasn't likely to be a source of Europe's dominance. This is not to say that land ownership is unimportant, land ownership is vital for environmental reasons such as creating incentives to maintain the long term productivity of land.

[Edit: typos]