Who is Fyodor from Dreams of My Russian Summers and what is their importance?

Fyodor is Charlotte's husband who is arrested on New Year's day while dressed as Santa Claus. After his arrest, Fyodor is sent to a "repatriation" camp that should have kept him away for a few weeks, but actually keeps him away for five years. During this time away, Charlotte receives two letters stating Fyodor's death, but she refuses to believe them.