Gladstone's recent biographers - most notably H. C. G. Matthew - have discussed his friendships with women, ranging from aristocrats to courtesans. Regarding his thirty-year friendship with Mrs. Laura Thistlethwayte biographers retain a largely protective view - that Gladstone was tempted into a situation in which he became bound, yet maintained control. In re-assessing this intriguing relationship for the most intense period, 1865-75, this article suggests the reverse - that Gladstone had free choice and, for much of this time, was acting under circumstances more serious, and therefore more challenging of that control, than acknowledged. The precise nature of the relationship remains a mystery. However, re-examination of documentary sources and study of information previously omitted, as well as additional diaries, correspondence and Gladstone's reading, facilitate further understanding of that relationship and of Gladstone himself.