HENRY: Once more unto the breach, dear friends, once more;
Or close the wall up with our English dead!
In peace, there’s nothing so becomes a man,
As modest stillness and humility:
But when the blast of war blows in our ears,
Then imitate the action of the tiger;
Stiffen the sinews, summon up the blood,
Disguise fair nature with hard-favored rage ….

William Shakespeare (1564-1616) English dramatist and poet

Henry V, Act 3, sc. 1, l. 1ff (3.1.1-8) (1599)
    (Source)