The emphasis on duty is clear in all of his dealings with his son. Alphonse dies of an apoplectic fit after hearing of the death of Elizabeth.

Does Alphonse die in Fullmetal Alchemist?

Alphonse Elric – Sacrificed himself to restore Ed's arm, reversing the transmutation that put him in the armor. He was revived when Ed sacrificed his Gate of Truth and ability to use alchemy.

What happened to Alphonse?

Alphonse he lost his body when he and Edward try to revive their mother Trisha using alchemy. Edward sacrifices his right arm to seal Alphonse's soul into a suit of armor. ... After the two are successful in their plan, Alphonse's original body tries to recover the soul resulting in him losing consciousness several times.