In attempt to broaden its online audience, The Washington Post Company on Monday is to introduce an online magazine primarily for a black audience, with news and commentary on politics and culture, and tools for readers to research their family histories.

Henry Louis Gates Jr., a writer and a professor of African and African-American studies at Harvard, is the editor in chief of the magazine, called The Root, which he conceived with Donald E. Graham, chief executive of the company. The magazine is based in Washington, free to readers and will be found at www.theroot.com.

Several well-known authors and scholars have agreed to contribute to The Root, including Malcolm Gladwell and William Julius Wilson. The managing editor is Lynette Clemetson, who was until recently a reporter in Washington for the The New York Times and previously was a national and foreign correspondent for Newsweek.