Complex sentence: In 1836 Viardot, who was already a friend of the artist Ary Scheffer, was attorney of Maria Malibran and managed her matter, and her marriage with Eugene Malibran was terminated in 1836 with his help.
Split into simpler sentences: In 1836 Viardot, who was already a friend of the artist Ary Scheffer, was attorney of Maria Malibran and managed her affairs. Her marriage with Eugene Malibran was terminated in 1836 with his help.