* 1900 – Leo Robin, American songwriter and composer ( d. 1984 )

He collaborated on the score for the 1955 musical film My Sister Eileen with Leo Robin.

His collaborators included, among others, Sammy Cahn, Leo Robin, Betty Comden and Adolph Green, Stephen Sondheim, and Bob Merrill.

* December 29 – Leo Robin, American composer ( b. 1900 )

: Lyrics by Leo Robin

: Lyrics by Leo Robin

: Lyrics by Leo Robin

: Lyrics by Leo Robin

: Lyrics by Leo Robin

: Lyrics by Leo Robin

: Lyrics by Leo Robin

: Lyrics by Leo Robin

* " June In January " w. Leo Robin m. Ralph Rainger Movie: " Here Is My Heart "

* " Love In Bloom " w. Leo Robin m. Ralph Rainger

* " Love Is Just Around The Corner " w. Leo Robin m. Lewis E. Gensler

* " With Every Breath I Take " w. Leo Robin m. Ralph Rainger

* " I Have To Have You " Leo Robin, Richard A. Whiting

* " Louise " w. Leo Robin m. Richard A. Whiting.

* " My Ideal " w. Leo Robin m. Richard A. Whiting & Newell Chase.

Sam Coslow, Leo Robin & Richard A. Whiting

* " Wait ' Til You See Ma Cherie " w. Leo Robin m. Richard A. Whiting

" w. Leo Robin & Clifford Grey m. Vincent Youmans

* " Awake in a Dream " w. Leo Robin m. Frederick Hollander.

Leo Robin & Richard A. Whiting.

* " If I Should Lose You " w. Leo Robin m. Ralph Rainger.

In 1882 Pope Leo XIII had a Mass and an Office composed for his feast day, which he set at 14 April, the day after the day indicated as that of his death in the Martyrology of Florus ; but since this date quite often falls within the main Paschal celebrations, the feast was moved in 1968 to 1 June, the date on which he has been celebrated in the Byzantine Rite since at least the 9th century.

In April of the same year, Dr. Leo Alexander had submitted to the Counsel for War Crimes six points defining legitimate medical research.

# Leo XI ( 1 – 27 April 1605 ): reigned for 27 calendar days

Milligan was born in Ahmednagar, India, on 16 April 1918, the son of an Irish father, Captain Leo Alphonso Milligan, MSM, RA ( 1890 – 1969 ), who was serving in the British Indian Army.

On 7 April 2010, 3AW reported that Skyhooks were to appear on the first episode of the new series of Hey Hey It's Saturday with Leo Sayer on vocals.

A reunion telefilm, The Return of the Man from U. N. C. L. E., subtitled The Fifteen Years Later Affair, was broadcast on CBS in America on April 5, 1983, with Vaughn and McCallum reprising their roles, and Patrick Macnee replacing Leo G. Carroll as the head of U. N. C. L. E.

On April 20, 1884 Pope Leo XIII published an encyclical, Humanum Genus, that said that the human race was

* April 6 – Leo Aryeh Mayer, Israeli professor and scholar of Islamic art ( b. 1895 )

* April 25 – Leo Najo, American baseball player ( b. 1899 )

* April 1 – Pope Leo XI succeeds Pope Clement VIII as the 232nd pope.

* April 27 – Pope Leo XI ( b. 1535 )

* April 13 – Pope Victor II succeeds Pope Leo IX as the 153rd pope.

* April 19 – Pope Leo IX ( b. 1002 )

Pope Saint Leo IV was pope from 10 April 847 to 17 July 855.

Pope Leo XI ( 2 June 1535 – 27 April 1605 ), born Alessandro Ottaviano de ' Medici, was Pope from 1 April 1605 to 27 April of the same year.

On 1 April 1605, Alessandro ascended the papal throne with the name Leo XI after his uncle Pope Leo X, being then almost seventy years of age, but was taken ill immediately after his coronation and died within the month.

At the very time of Leo's accession Louis XII of France, in alliance with Venice, was making a determined effort to regain the duchy of Milan, and Leo, after fruitless endeavours to maintain peace, joined the league of Mechlin, on 5 April 1513, with the emperor Maximilian I, Ferdinand II of Aragon, and Henry VIII of England.

On 9 December 1513, the fifth Lateran council, which had been reopened by Leo in April, ratified the peace with Louis XII and officially registered the conclusion of the Pisan schism.

The same desire for peace and the death of Pope Leo ( April 19 ) were reasons why Hildebrand did not press for Berengar's going to Rome at once.

* April 12 – Emperor Leo I has his general Anthemius elected emperor of the Western Roman Empire.

In April 1914 Leo relocated to Settignano, Italy, near Florence, and the art collection was divided.

Pope Saint Leo IX ( 21 June 1002 – 19 April 1054 ), born Bruno of Egisheim-Dagsburg, was Pope from 12 February 1049 to his death.