Here is the full list of all 30 The Eagles Heir achievements.
Crash an airship.
Become a racing champion.
Fight a duel with Franz at the Tuileries.
Win more than one duel.
Finish the game without drawing your sword or firing a shot.
Have romances with two NPCs.
Have romances with three NPCs.
Have a threesome at the Tuileries.
Persuade Alexandre to abandon his throne to be with you.
End the game with Franz on the throne.
End the game in a republic.
End the game with Alexandre on the throne.
See Alexandre become prince consort of Great Britain.
See Alexandre become the ambassador to Great Britain.
See Victoria become empress of France.
See Eugenie become empress of France.
Flee to New Orleans.
Be awarded the Legion of Honor.
Prevent Cassius's death if his revolution fails.
Make a last stand at the Hôtel de Ville and survive.
Persuade Victoria to elope with Alexandre.
Persuade Napoleon to legitimize Alexandre.
Persuade Napoleon to declare a republic.
Reconcile Alexandre and Franz.
Kill Amalia.
Kill Franz.
Save Franz's life.
Kill Alexandre.
Die saving Alexandre's life.
Be guillotined for your crimes.