May 16, 1943:
As Brits launch Operation Chastise, Germans launch Operation Gypsy Baron

May 17, 1943:
The United States Army contracts with the University of Pennsylvania's Moore School to develop the ENIAC.

May 19, 1935:
Lawrence of Arabia dies

T.E. Lawrence, known to the world as Lawrence of Arabia, dies as a retired Royal Air Force mechanic living under an assumed name. The legendary war hero, author, and archaeological scholar succumbed to injuries suffered in a motorcycle accident six days before.
Thomas Edward Lawrence was born in Tremadoc, Wales, in 1888. In 1896, his family moved to Oxford. Lawrence studied architecture and archaeology, for which he made a trip to Ottoman (Turkish)-controlled Syria and Palestine in 1909. In 1911, he won a fellowship to join an expedition excavating an ancient Hittite settlement on the Euphrates River. He worked there for three years and in his free time traveled and learned Arabic. In 1914, he explored the Sinai, near the frontier of Ottoman-controlled Arabia and British-controlled Egypt. The maps Lawrence and his associates made had immediate strategic value upon the outbreak of war between Britain and the Ottoman Empire in October 1914.

On May 23, 1701:

In London, Captain William Kidd was hanged after being convicted of murder and piracy.

On May 25, 1787:

The Constitutional convention opened in Philadelphia with George Washington presiding.