Character Analysis
Joseph is sort of the strong but silent type. He's strong because he tends for Sophie in what's an incredibly patient, loving way: he's a bedrock. And he's silent because… we don't actually learn very much about Joseph in this work.
He's more of a character sketch than a fully realized character, maybe because he is external to the Caco family network. Joseph mainly stands on the sidelines really wondering how he can reach his wife, Sophie, and relieve her suffering.
Sophie tells us that she's truly in love with Joseph, even if she's a little starstruck at the beginning of their relationship.
I was eighteen and I fell in love. His name was Joseph and he was old. He was old like God is old to me, ever present and full of wisdom. He looked somewhat like Monsieur Augustin. He was the color of ground coffee, with a cropped beard and a voice like molasses that turned to music when he held a saxophone to his lips. (9.67)
While this isn't the most complimentary description, in the history of descriptions—old like God? dang, he must be hot!—it is totally Sophie. She sees the world in cosmic terms, since she values the stories of her childhood so highly. Joseph—conveniently named after the Virgin Mary's old and patient husband—doesn't really need a fully realized character to fulfill his role in this work.
He has to be enchanting enough to attract Sophie (like the lark who charms the little girl) and willing to give her the space she needs to work out her relationship with Martine and the conflicts of the past.
Joseph's Timeline