This video from a documentary series “Greatest Tank Battles” details the first use of tanks in battle during Word War I, where the British introduced their use in 1916, surprising thousands of German troops who were dug into trenches not realizing what was being unleashed on them.  Also explained is what happened when Germany introduced their own tanks in 1918.

[Note: This is interesting information, but I think it is ridiculous when extreme aspects of war are described using the word “great” which usually has positive connotations.]