Complex sentence: He rarely stayed for more than two weeks until 1997, when his friend Jonathan Silver who was terminally ill encouraged him to capture the local surroundings, which he did at first with paintings based on memory, some from his boyhood.
Split into simpler sentences: He rarely stayed for more than two weeks until 1997, when his friend Jonathan Silver who was terminally ill encouraged him to capture the local surroundings. He did this at first with paintings based on memory, some from his boyhood.