It's a long read, and the writing is at times in need of an editor, but the content is interesting, accurate and food for thought.
[samilhistory.com]debunking-the-myth-that-the-british-invented-the-concentration-camp/
"Debunking the Myth that the British Invented the Concentration Camp."
Actually, they may have been Roman inventions. The Romans were fond of forcing conquered peoples onto tracts of useless land, in the fervent hopes that they would starve to death (pre-dating the U.S. government's Indian "Reservations" by 1,400 years or so). Which is why, in 410 A.D., Alaric, a Visigoth war chief led his people 'off the reservation' to sack Rome.
Not quite the same. They did not have the ultra-high population densities, and they had internal autonomy.
Modern day Gaza almost merits the concentration camp label, though.