Complex sentence: In late 1866, the family moved back to Port au Prince, where Frier continued his work with the military bands, until he died suddenly on March 17,1869, when he had finished his mission and had packed their household to return to France.
Split into simpler sentences: In late 1866, the family moved back to Port au Prince, where Frier continued his work with the military bands, until he died suddenly on March 17,1869. He had finished his mission and had packed their household to return to France.