It was revealed that John Sayers, 25, showed 'no mercy' when he repeatedly assaulted Eileen Schneider, his girlfriend of two years, in a fit of jealous rage.
Truro Crown Court heard that Sayers' violent outbursts started while they were on a tour of Europe, but he promised to change but his brutality only escalated when they moved to his mother's house in Truro, Cornwall.
On Friday, Judge Harvey Clark told Sayers: "Your jealousy led you to assault her on frequent occasions with punches and kicks.
"You threatened her with a knife. You would put your hands around her throat causing her to choke and lose consciousness.
"On at least two occasions you threatened to kill her. On one occasion you put a handgun into her mouth.
"You intended to put her in fear of her life. Not surprisingly, you succeeded in that."
The judge added that on June 28 and July 2, Sayers attacked Miss Schneider 'without mercy', using his fists to inflict injury on her, and kicking her all over her body.
He said: "On July 2 you took a kitchen knife into her mouth and threatened to cut off her tongue. You told her she was lucky not to have a broken jaw.
"In my judgement, you manipulated and terrorised her.
"She was reduced to a timid, helpless girl living in a foreign country and unable to contact her family in Germany because you had removed her mobile phone."
He then proceeded to sentence Sayers to five years in prison, to serve a minimum of three years before being released on licence.