re age -
"The youngest known soldier of World War I was Momčilo Gavrić, who joined the 6th Artillery Division of the Serbian Army at the age of 8, after Austro-Hungarian troops in August 1914 killed his parents, grandmother, and seven of his siblings."
from http://en.wikipedia.org/wiki/Military_use_of_children
more recently
http://www.rferl.org/content/Child_Soldiers_Of_The_Balkans/1349516....