h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

i remember reading somewhere the thesis that personal wealth depends on land ownership - ie. those countries that have lots of land and impoverished citizens are those in which land ownership is controlled by heads of tribes, or by government, or by... and those countries in which land can be freely bought & sold are those with the wealthiest citizens.

I have also heard it said that all title to land originally derives from forcible takeover. true?

finally, what does it mean to "own land?" how has this definition, whatever it is, evolved (ie. if land ownership changes economy, does economy also change ownership?)