Born at Gosberton, near Spalding, Lincolnshire, the son of a farmer. Educated at University College School and University College, London, and received his professional training at St. Thomas's Hospital, where he was House Surgeon and Demonstrator of Anatomy in the Medical School. He started practice in Fenchurch Street, EC, where his partner was Charles Brodie Sewell. The City was at that time still somewhat of a residential quarter, and Messrs Sewell and Crosby enjoyed a busy practice among City families. Later he moved to Finsbury, where he enjoyed a large practice in a recognized medical district less than fifty years ago. His connection with municipal affairs dated from 1877, when he was elected a Common Councillor of the City for the Langbourn Ward. In 1898 he became Alderman for the same Ward. In 1906-1907 he was one of the Sheriffs, and during his year of office he paid, with other representatives of the Corporation, a visit to Berlin as the guest of the Municipality of that City. He was knighted the same year (1906). Being the senior Alderman below the Chair in 1911, he was elected Lord Mayor of the City of London. He was then 82 years of age, and the choice of the City gave him the double distinction of being the first medical man to occupy the civic chair in the metropolis, and of being the oldest citizen who had ever undertaken the responsibilities of Lord Mayor of London. He was conscientious and untiring in carrying out his official duties, his daughter assisting him as Lady Mayoress. On a notable occasion he dined at the Royal College of Surgeons, and his Lord Mayoralty is marked by two important events - the tragedy of the sinking of the White Star passenger steamship Titanic, and a coal strike, which at that time was regarded as threatening a national disaster. A Mansion House Fund for the sufferers by the foundering of the great ship was immediately opened, and £450,000 was raised. In a critical stage of the coal strike he convened at a few hours' notice a meeting of Lord Mayors, Mayors, and Provosts from all parts of the country, and the resulting intention on the part of the municipalities to take concerted action against impending danger did much to relieve the stress of a dangerous social situation. On retiring from the position of Lord Mayor the vote of thanks accorded to him in Common Hall was especially cordial, as it was recognized that he had used his civic position with great promptitude in the public cause. In private life Sir Thomas Crosby was a shrewd, witty, kind, homely man, and his success was the outcome of persistent habits of hard work and self-restraint. He had no great learning, but he was an admirable magistrate, whose decisions were informed throughout with that real knowledge of the life of the people which the successful and industrious general practitioner cannot fail to possess. He died after a brief illness on April 7th, 1916. His London addresses were at 19 Gordon Square, WC, and Cullum House, 136 Fenchurch Street, EC. There is a good portrait of him in his Lord Mayoral robes in the *St Thomas's Hospital Gazette* (1911, xxi, 293), and another in the *Lancet* (1916, I, 836, 884).