Complex sentence: He was a cousin (and for some time a lover) of Lytton Strachey: through the Stracheys Duncan was introduced to the Bloomsbury Group, where Maynard Keynes became another of his lovers.
Split into simpler sentences: He was a cousin, and for some time a lover, of Lytton Strachey. Through the Stracheys, Duncan was introduced to the Bloomsbury Group, where John Maynard Keynes became another of his lovers.