By what pseudonym is writer Frederic Dannay and Manfred Bennington Lee better known?

Ellery Queen is a crime fiction house name created by Frederic Dannay and Manfred Bennington Lee, and later used by other authors under Dannay and Lee's supervision. Books using this pseudonym were written from 1929 to as late as 1973. Dannay and Lee's main fictional character, whom they also named Ellery Queen, is a mystery writer who helps his father Richard Queen, a New York City police inspector, solve baffling murders.

Most of the thirty plus novels and several short story collections in which Ellery Queen appeared as a character were written by Dannay and Lee. Other authors were commissioned and supervised by Dannay and Lee to write crime thrillers under the Ellery Queen authorial name, but not featuring Ellery Queen as a character.

Daniel Nathan, professionally known as Frederic Dannay (October 20, 1905 – September 3, 1982), and Emanuel Benjamin Lepofsky, professionally known as Manfred Bennington Lee (January 11, 1905 – April 3, 1971), were American cousins from Brooklyn, New York.

In addition to writing most of the novels and short stories featuring the brilliant amateur detective Ellery Queen, Dannay and Lee edited more than thirty popular anthologies of crime fiction and true crime, which were also published under the Ellery Queen pseudonym. Dannay was the founder and longtime editor of Ellery Queen's Mystery Magazine, which has been published continuously from 1941 to the present.