principal

distinguished, eminent, illustrious, noble, notable, noteworthy, outstanding, prestigious, signal, star, stellar, superior

high-level, senior, top

important, influential, major, mighty, momentous, significant

incomparable, matchless, unequaled (or unequalled), unparalleled, unsurpassed

celebrated, famed, famous, renowned

high-level, senior

controlling, directing, managing, officiating, overseeing, regnant, reigning, ruling, supervisory

main, major, paramount, predominant, predominate, sovereign (also sovran)

ascendant (also ascendent), dominant, grand, superior, topmost, upmost, upper, uppermost