Complex sentence: Pierre Janelle published a study on Southwell in 1935 in which he recognized him as a pioneer Baroque figure, one of the first Baroque writers of the late 16th century and influential on numerous Baroque writers of the 17th century.
Split into simpler sentences: Pierre Janelle published a study on Southwell in 1935 in which he recognized him as a pioneer Baroque figure. He was one of the first Baroque writers of the late 16th century and his works influenced numerous Baroque writers in the 17th century.