This is a splendidly-mounted production by anyone's standards; arguably it is the best realization of the pre-Elizabethan, the late Marian period ever realized on film.   But despite its modest beginnings as a fictionalized biography of Elizabeth Tudor by popular author Margaret Irwin, the screenplay by Jan Lustig and Arthur Wimperis also adds another dramatic dimension to a well-told story.  The subject in this work is the dangerous, difficult and famous youth of the future Elizabeth Ist of England, taking her from childhood to her accession to the throne after the death of her sister Bloody Mary, who reigned following the death both of King Henry VII and his frail son and heir Arthur, who died at 12 years of age.  George Sidney directed this dignified and powerful story;  and the assembled cast he presented were well-chosen as speakers of the English language:  Jean Simmons playing the young Elizabeth with unusual intelligence and verve; Cecil Kellaway as the loyal warder who looks after her modest household as a princess out of favor;  Charles Laughton reveling in his bravura role as the irascible and fascinating Henry VIII;  Stewart Granger and Guy Rolfe playing the rival brothers who wrestle for control of England's political direction; Deborah Kerr as the King's last wife, gentle an d lovely Catherine Parr; also prominently featured were Kathleen Byron, Kay Walsh, young Rex Thompson as Edward, Elaine Stewart, Dawn Addams, Ivan Triesault, Lumsden Hare, Leo G. Carroll, Doris Lloyd, Norma Varden, Alan Napier, Robert Arthur and Lester Mathews. The plot-line concerns Elizabeth's attempts to survive the shifting fortunes of the English court; powerless, except for the loyalty of a few noblemen, her greatest danger comes from the handsome and ambitious Thomas Seymour (Granger); the script treats his regard for Elizabeth as political, which is not historical; by attaching himself to the queen of the late King Henry, he becomes so dangerous his unpleasantly Establishment and puritanical brother Edward must move against him. from this loss, Elizabeth is fortunate to emerge alive and, at last, queen of England; but this is a moving film that touches on her relative poverty, fears, learning, arguments with her father, disappointment when Edward who loves her dies, and her last danger in the Seymour's quarrel. The emotionally rich film is superbly served in my estimation by Miklos Rozsa's memorable score. With bright cinematography by Charles Rosher, brilliant art direction by Cedric Gibbons and Urie McCleary, set decorations by Jack D, Moore and Edwin Willis and gorgeous costumes by Walter Punkett, the film is very attractive to watch in every scene. Sydney Guilaroff's hairstylings, William Tuttle's makeup and Douglas Shearer's sound work are all first-rate as well. The best scene in the film to many minds is the argument aboard a ship between the volatile Henry Tudor and his equally spirited daughter; but this is a very good film, on the verge of being a great one, thanks to director Sidney's solid presentation of every scene of the material. I recommend it highly, if not as literal history then as a colorful, thoughtful and satisfying entertainment.