Complex sentence: Laurence married Anastasia Gliddon, cousin and adopted sister of Mrs. Thornton Leigh Hunt, and during his early married life he visited Florence and Venice, studying diligently the methods of the old masters, and endeavouring to discover the secrets of their success.
Split into simpler sentences: Laurence married Anastasia Gliddon, cousin and adopted sister of Mrs. Thornton Leigh Hunt, and during his early married life he visited Florence and Venice. There, he diligently studied the methods of the old masters, and endeavouring to discover the secrets of their success.