And once a great king ruled, but then one mistake brought him to his knees, and then he was gone.

10 seconds sound clip from the Strife for Mastery (1978) movie soundboard.

You can hear this line at 01:06:42.167 in the DVD version of the movie.

Quote context

[...]

- That's enough talk. Let's just finish him now.

- When will master come?

- He's waiting for our message.

- I served our master for nearly three years, but never once have I seen his face yet.

- I know he's a very mysterious man. No one knows anything about him. I mean, I know that he manages to control us, but I don't know how.

- One time I thought he might be the young brother, but then...

- And once a great king ruled, but then one mistake brought him to his knees, and then he was gone.

- Young master.

- What is it? Some trouble?

- Young master, I've discovered who killed your father.

- Who was it? Tell me.

- You did, young master.

- Nonsense, who was it?

- You, it was you because you wanted to take your father's place here, and so you killed your father, and you blamed your brother.

[...]