Complex sentence: Azzo's first wife Elisa, a daughter of a count Aldobrandino, was dead by 1192, by which time he had remarried to a daughter of Humbert III of Savoy, named either Sophia or Eleanor (as per the epitaph of their daughter Beatrice).
Split into simpler sentences: Azzo's first wife Elisa, a daughter of a count Aldobrandino, was dead by 1192. By 1192 he had remarried to a daughter of Humbert III of Savoy, named either Sophia or Eleanor (as per the epitaph of their daughter Beatrice).