Disciplinarian

Noun

 * 1) One who exercises discipline.
 * He is the chief disciplinarian in the school.
 * 1)  One who believes in discipline as a tool for regulation or control.

Related terms

 * disciple

Adjectives
harsh; ferocious; stern; incompetent; ineffectual; strong-minded

Thesaurus
Simon Legree, absolute monarch, absolute ruler, all-powerful ruler, arrogator, autarch, autocrat, caesar, commissar, czar, despot, dictator, driver, duce, hard master, martinet, oligarch, oppressor, pharaoh, slave driver, stickler, taskmaster, tyrant, usurper, warlord

Etymology
or