Looking for 80s/90s fantasy movie; king turns into hawk, statue of head

I'm looking for the title of a movie I once saw as a kid and liked immensely. I've previously posted this request to the I Need To Know board, with no results; and repeated googling spread out over several years turns up nothing (mainly because I'm unsure about key specifics). I've also searched for (and looked at) all imdb fantasy films from the relevant period and found nothing (but there's lots of movies/episodes without description). I hope one of you people can help me.

Some specifics I can remember:

* Late 1980s, early 1990s, I believe. May have been earlier. Not later than 1999.
* I believe the story started with some kingdom under attack, and the royal heir, still a baby, is smuggled away by a band of trustees to reclaim his kingdom when he's grown up.
* A hawk (or a falcon or an eagle or another brown bird of prey) flies over a basket with the heir and deposits a medallion or an amulet of some sort on the baby's blankets.
* This medallion/amulet grants the heir magical powers. When the heir is grown up, he wears it as a belt clasp and twists it -- to make it fulfill his wishes?
* I remember him scaring his love interest, in some castle room (has he regained his kingdom by then?) by suddenly letting the hearth fire flare up. He wants to impress her, but she's scared and reluctant to acknowledge how great this magic is. He hugs her, but she's not comforted.
* The heir abuses his power. He turns evil and he starts to look more like a hawk. His face gets disfigured, and his nose looks more and more like a beak. Before that he was handsome, with long blond hair.
* Every time he misuses his power, he looks a little more like a bird -- crooked, down growing on his face, nose like a beak.
* In the end his love interest flees with a couple of his former lieutenants (or something -- at any rate, she's not alone), because he's become such a monster. I think there's a scene in which he kills the love interest and her company, again by twisting the medallion. There's flashes of them hurrying through windy fields on horseback as stormclouds gather. I believe the girl and her company die in a hail of lightning (but I'm unsure about that point)I vaguely recall someone or something egging the hero on, urging him to use his magic against those who rejected him.
* There might be some shadowy figure accompanying him throughout the movie who encourages him to use his magic for evil.
* I remember the film ended with the hero renouncing his power or something. He finally rejects the figure that's been driving him into evil. I believe he also dies -- maybe he performs a last wish undoing all his evil deeds? The final shot was a swooping aerial shot of a giant statue of his hawk-head that had magically reverted to his earlier, handsome face.

It might not have been a stand-alone movie, but rather an episode of a show with fairy-tale like stories, or part of a series of fantasy films.

It is not:

- One of the Jim Henson Storyteller episodes
- Ator, The Fighting Eagle
- Hawk The Slayer
- Dragon's Lair
- Krull
- Legend
- LadyHawke

As before, I'll bump this three times before giving up on the thread.
I'll be grateful for any suggestions. Thanks in advance!