The earliest reference I remember for this phrase is:
William Shakespeare's, King Henry V
Act IV, Scene III
"We few, we happy few, we Band of Brothers, For he to-day that sheds his blood with me shall be my brother; be he ne'er so vile, this day shall gentle his condition;
And gentlemen in England now a-bed shall think themselves accursed they were not here, and hold their manhood's cheap whiles any speaks that fought with us upon Saint Crispin's day. "
There you go. I was in the throes of tunnel vision. Thank you.