Descendants of Vikings and Mongolians do not current hold title over the land they have historically conquered.

The allies gave West Germany back to Germans in 1949.

The Soviets lost East Germany back to the Germans in 1990.

Whites being given back their land after losing the war did happen only recently.

South Americans had their land returned by Spanish and Portguese forcefully.

Japan had it's country returned. China had Hong Kong returned.

New Zealand Maori's received financial reparations.

So are you suggesting only everyone else get their land back, and indigenous australian's, well.. water under the bridge kind of thing?