Until the publication of The Letters of Jonathan Swift to Charles Ford, literary scholars thought that Swift wrote Gulliver's Travels between 1715 and 1720, a period when he published almost nothing. His starting point was, they believed, sketches made up by the Scriblerus group—Pope, Swift, and others—in 1713 and 1714, and finally produced by Pope in 1741. Then D. Nichol Smith, in his edition of the Ford letters, proved that Swift wrote Part i of Gulliver in about 1721–22, Part ii around 1722–23, Part iv in 1723, and Part iii (after Pt. iv) in 1724–25. Swift continued to revise it, probably until it was published in the autumn of 1726.