Another word for fulfill

Barclay de Tolly tried to command the army in the best way, because he wished to fulfill his duty and earn fame as a great commander.
Boris promised to fulfill her wish and was about to begin a conversation with her, when Anna Pavlovna called him away on the pretext that her aunt wished to hear him.
'Grant leave to retire to his country seat to an old man who is already in any case dishonored by being unable to fulfill the great and glorious task for which he was chosen.
Anisya Fedorovna, with her light step, willingly went to fulfill her errand and brought back the guitar.
That same evening Pierre went to the Rostovs' to fulfill the commission entrusted to him.