Hoyer was born in Gube, East Germany, where her mother was a teacher and her father an East German military officer.

She received a Master's degree from the University of Jena and moved to the UK in 2010.

Hoyer is a visiting research fellow at King’s College, London and has published two books about the history of Germany.

She is also a journalist for The Spectator, The Washington Post and Die Welt.

Her first book, Blood and Iron, about the German Empire from 1871 to 1918, was well reviewed, even though some reviewers suggested that she had played down the negative aspects of the period and of Otto von Bismarck’s legacy. Her second book, Beyond the Wall, about the history of East Germany from 1949 to 1990, was well-reviewed in the UK but less well-received in Germany.