Warning: this story contains spoilers for Sunday's "The Lucky Ones" episode of The Walking Dead. "Who's Deanna?" asks Abraham Ford (Michael Cudlitz) when arriving at the Alexandria Safe-Zone in Season 5 of The Walking Dead. Led by Rick Grimes (Andrew Lincoln), the group of zombie apocalypse survivors soon find out when they meet Reg (Steve Coulter) and Deanna Monroe (Tovah Feldshuh): the first leader of Alexandria. Years later, when Daryl (Norman Reedus) reminisces about Deanna in "The Lucky Ones," it's revealed she knew Governor Pamela Milton (Laila Robins) of Ohio's Commonwealth community.
Looking at a framed photo of Reg and Deanna, Governor Milton says she and Deanna "used to cross paths quite a bit in philanthropy circles back in the day." The daughter of a former president of the United States, Milton had no interest in politics at the time. Remembering Deanna, Milton says she "was born to run things."
A twice-elected U.S. Congressperson for Ohio's 15th district, Deanna settled into Alexandria with Reg and their sons Aiden (Daniel Bonjour) and Spencer (Austin Nichols). In Season 5 episode "Remember," it's revealed the Monroes ended up in Alexandria at the direction of the Army as they attempted to return to Ohio in the early days of the walker apocalypse.
Reg, a professor of architecture, used supplies from a nearby under-construction shopping mall to build the walls around Alexandria. In time, more people arrived at Alexandria and helped build the community.
Aaron (Ross Marquand) informs Milton Deanna was bitten and had to be put down after she turned. Deanna dies when a walker horde invades Alexandria in the Season 6 episode "Start to Finish," and Spencer puts his zombified mother to rest in "The Next World."
In the comic books by Robert Kirkman and Charlie Adlard, Deanna's counterpart is Douglas Monroe, a U.S. Congressman turned leader of Alexandria.