spartan

adjectives

resolute in the face of pain or danger or adversity
"spartan courage"
is similar to
firm in purpose or belief; characterized by firmness and determination
"stood resolute against the enemy"; "faced with a resolute opposition"; "a resolute and unshakeable faith"
unsparing and uncompromising in discipline or judgment
"a parent severe to the pitch of hostility"- H.G.Wells; "a hefty six-footer with a rather severe mien"; "a strict disciplinarian"; "a Spartan upbringing"
practicing great self-denial
"Be systematically ascetic...do...something for no other reason than that you would rather not do it"- William James; "a desert nomad's austere life"; "a spartan diet"; "a spartan existence"