Complex sentence: Throughout his career, Waterhouse was preoccupied with the poetry of both Tennyson and John Keats, and between 1886 and 1894 he painted three episodes from the former's epic.
Split into simpler sentences: Throughout his career, Waterhouse was preoccupied with the poetry of both Tennyson and John Keats. Between 1886 and 1894 Waterhouse painted three episodes from the former's epic.