Whitaker, Joseph, 1820-1895. An Almanack...by Joseph Whitaker, F.S.A., Containing an Account of the Astronomical and Other Phenomena…Information Respecting the Government, Finances, Population, Commerce, and General Statistics of the Various Nations of the World, with Special Reference to the British Empire and United States. London: 1868-
Perkins/Bostock stacks AY754 .W5
Library has: 1872 to present.
Especially convenient because there have been annual volumes since 1869. The comprehensive register of civil, military, and ecclesiastical officials also includes some businesses as well as many public and private schools and other institutions. The section for foreign countries lists the English diplomats resident there and the foreign representatives in London. Principal governmental officials and rulers are also listed. The section on colonies includes their major administrators.

The Statesman's Year-book; Statistical and Historical Annual of the States of the World... Revised After Official Returns. London, New York: Macmillan and CO., Ltd., 1864-
Perkins/Bostock Stacks JA51 .S7
Library has: 1864-1867, 1870, 1872-1874, 1877-1881, 1885-1887, 1892-1957, 1959 to present.
Arranged by colonies and countries. In the mid-1870's, lists of diplomatic representatives to and from Great Britain were added to the information about each foreign country. Rulers and major governmental officials are also included.