Complex sentence: The author became friendly with the American dancer Isadora Duncan towards the very end of her life when she was penniless and alone and in 1928 wrote a memoir of his conversations with her entitled "Isadora, an Intimate Portrait", shortly after her death.
Split into simpler sentences: The author became friendly with the American dancer Isadora Duncan towards the very end of her life when she was penniless and alone. In 1928 he wrote a memoir of his conversations with her, "Isadora, an Intimate Portrait", shortly after her death.