Complex sentence: In 1817 Champollion read a review of his "Égypte sous les pharaons", published by an anonymous Englishman, which was largely favorable and encouraged Champollion to return to his former research.
Split into simpler sentences: In 1817 Champollion read a review of his "Égypte sous les pharaons", published by an anonymous Englishman, who was largely favorable. It encouraged Champollion to return to his former research.