Complex sentence: The two soon began a relationship, but canon law appeared to rule out marriage; when Kent travelled to London to seek advice he was told that as Elizabeth had borne him a living son, a union with Fanny was impossible.
Split into simpler sentences: The two soon began a relationship, but canon law appeared to rule out marriag. Kent sought legal advice in London and was informed that as Elizabeth had borne him a living son, a union with Fanny was impossible.