This idea refers to how the final, absolute owner of an area of land and other similarly substantive property, may be defined, or identified.

A problem here, is that European culture is rooted in the idea that only their civilization understood how to own land. As a result, concepts and practices of land ownership in most of those parts of the world that have experienced European domination, tend to be measured and understood from when the European introduced their version of it.

This has resulted in the notion that Radical Title, lay with whoevers’ ownership had been recognized by the first colonizing European power to have arrived at the time, within that European system.
Sometimes, this has led to some natives having their land ownership initially acknowledged. Other times, it has allowed the wrong people –such as neighbors to those natives, or influential clans among them, or even invading alien races of white settlers- to put themselves forward as the “original” owners of a territory.

In general terms, it was the European-planted state that assumed itself to be the holder of radical title to the land of the territory in question, and the one entitled to make that land available to others through various types of arrangements.
But this idea can be challenged by any natives proving they were present there even before the arrival of the European-planted state, whether it made acknowledgement of their existence or not, at the time.

This should be called the Radical title: a claim to ownership that does not require the presence or the laws of the European-planted state to validate it, and that may have to neutralize the claim by that state, in order to assert itself.