c'en est fait, it's all over with that.
Horace, Horatius, the hero of Corneille's tragedy Horace, one of three brothers who fought for Rome against the Alban brothers Curiatii, who were their relatives by marriage. In speaking to his brother-in-law of the approaching fight Horace uses the words (Act II., Scene 3):
Albe vous a nommé, je ne vous connais plus,
a verse which is here parodied. For the story of the Horatii, see any classical dictionary.
un peu long because its former half has, when pronounced according to the rules of French prosody, seven syllables, while an alexandrine hemistich should have but six, as this will have if bonapartiste is spoken without the final e.