James Knox Polk ( /ˈpoʊk/ "poke"; November 2, 1795 – June 15, 1849) was the 11th President of the United States (1845–1849). Polk was born in Mecklenburg County, North Carolina. He later lived in and represented Tennessee. A Democrat, Polk served as the 17th Speaker of the House of Representatives (1835–1839) and Governor of Tennessee (1839–1841). Polk was the surprise (dark horse) candidate for president in 1844, defeating Henry Clay of the rival Whig Party by promising to annex Texas. Polk was a leader of Jacksonian Democracy during the Second Party System.

Polk was the last strong pre–Civil War president, and he is the earliest of whom there are surviving photographs taken during a term in office. He is noted for his foreign policy successes. He threatened war with Britain over the issue of which nation owned the Oregon Country, then backed away and split the ownership of the region with Britain. When Mexico rejected American annexation of Texas, Polk led the nation to a sweeping victory in the Mexican-American War, which gave the United States most of its present Southwest. He secured passage of the Walker tariff of 1846, which had low rates that pleased his native South, and he established a treasury system that lasted until 1913.

Dark horse is a term used to describe a little-known person or thing that emerges to prominence, especially in a competition of some sort or a contestant that seems unlikely to succeed.

The term began as horse racing parlance. A dark horse is a race horse that is not known to gamblers and thus is difficult to place betting odds on.

The earliest-known use of the phrase is in Benjamin Disraeli's novel The Young Duke (1831). Disraeli's protagonist, the Duke of St. James, attends a horse race with a surprise finish: "A dark horse which had never been thought of, and which the careless St. James had never even observed in the list, rushed past the grandstand in sweeping triumph."

The term has been used politically in such countries as Peru, Philippines and United States.

Politically, the term reached America in the nineteenth century when it was first applied to James K. Polk, a relatively unknown Tennessee Democrat who won the Democratic Party's 1844 presidential nomination over a host of better-known candidates. Polk won the nomination on the ninth ballot, and went on to win the presidential election.

James Robert Knox (2 March 1914 – 26 June 1983), an Australian Roman Catholic cardinal, was President of the Pontifical Council for the Family, between 1981 and 1983; a Prefect of the Congregation for Divine Worship and the Discipline of the Sacraments, between 1974 and 1983; and the fifth Archbishop of Melbourne, serving between 1967 and 1974.

Knox was born in Bayswater, Western Australia. He was a son of Irish–born John Knox and his wife Alice Emily, née Walsh. Attending Catholic schools in Perth, Knox applied to the Archdiocese to study for the priesthood, but was rejected because it was cheaper to recruit and educate priests in Ireland. He successful applied to become a priest at the Benedictine Territorial Abbey of New Norcia, and completed his secondary schooling at St Ildephonsus' College, before entering the seminary in 1936. By September that same year, he transferred to the Pontifical Urbanian Athenaeum in Rome.

Ordained priest on 22 December 1941, he pursued postgraduate studies, obtaining doctorates in theology (1944) and canon law (1949). Unable to return to Australia during World War II, he had been assigned to Propaganda College staff, becoming a vice-rector in 1945. He served as a staff member of the Vatican Secretariat of State from 1948 until 1950. He was also a staff member of Vatican Radio for a year between 1949 and 1950 and appointed to the rank of monsignor on 22 July 1950. He was Secretary to the Apostolic Delegate in Japan form 1950 until 1953.