Complex sentence: Arbella in Sir Thomas Perry's house in Lambeth and Seymour in the Tower of London; they had some liberty within those buildings, and some of her letters to him and to the king during this period survive.
Split into simpler sentences: Arbella in Sir Thomas Perry's house in Lambeth and Seymour in the Tower of London. The couple had some liberty within those buildings, and some of Arbella's letters to Seymour and to the King during this period survive.