premier

ancient, early, primal, primary, prime, primeval, primitive, primordial

antecedent, preceding, previous

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

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