Complex sentence: In 1901 he was elected to the Oxford professorship of poetry and during his five years in the post produced "Shakespearean Tragedy" (1904) and "Oxford Lectures on Poetry" (1909).
Split into simpler sentences: In 1901 he was elected to the Oxford professorship of poetry. During his five years in this post he produced "Shakespearean Tragedy" (1904) and "Oxford Lectures on Poetry" (1909).