Complex sentence: His first book, "The Social Milieu of Alexander Pope", was published in 1975 and sought to discover the historical context in which Pope wrote by analysing six figures who featured prominently in Pope's life and poetry.
Split into simpler sentences: His first book, "The Social Milieu of Alexander Pope", was published in 1975. In this work he sought to place Pope's work in historical context by analysing six figures who featured prominently in Pope's life and poetry.