The Alexander-Rideout Collection consists of material relating to Sir George Alexander and St. James's Theatre assembled by Alexander's distant relative, Nigel Rideout. The British actor-manager Sir George Alexander (1858-1918) was born Alexander George Samson in Reading, England. He began acting in amateur theatricals in 1875, and four years later embarked on a professional acting career, making his London debut in 1881. He played many roles in the leading companies, including Sir Henry Irving's Lyceum. In 1890 he produced his first play at the Avenue Theatre and in 1891 he became the manager of St. James's Theatre. Here he produced several of the major plays of the day such as Lady Windermere's Fan by Oscar Wilde (1892), The Second Mrs. Tanqueray by Sir Arthur Wing Pinero (1893), The Importance of Being Ernest by Oscar Wilde (1895), and The Prisoner of Zenda by Anthony Hope (1896).

The Maurice Willson Disher collection on Henry Irving and the Lyceum Theatre Company consists of material relating to the English actor Henry Irving (1838-1905) and the Lyceum Theatre company, assembled by Maurice Willson Disher (1893-1969), English critic and author. The bulk of the material, including correspondence, financial records, and memorabilia, survived a clearance of the Lyceum Theatre sometime after 1903. Disher purchased them at an auction.