Status Updates From Empires at War: A Chronolog...

Spartans are fearless warriors that had the best and most strict army of their century. Children where taken from their mothers at the age of 10 and they trained them to be warrior and those that weren’t fitted to be a warrior was thrown out and left out to die, they thought that it would cause weakness upon their society.

Note this is vol 1 out of 3.

Great book.