Haeften was born in
Berlin, the son of Hans von Haeften (1870–1937), an army officer and President of the
Reichsarchiv, and his wife the former Agnes von Brauchitsch (1869–1945), a relation of
Walther von Brauchitsch. His siblings were Elisabeth (1903–1980) and
Werner (1908–1944). He passed his
Abitur in 1924 in Berlin-Wilmersdorf and then studied law, which took him as an exchange student to the
University of Cambridge. He married Barbara Curtius (1908–2006), daughter of
Julius Curtius, on 2 September 1930. The couple had five children: Jan, Dirk, Verena, Dorothea, and Ulrike. After University, he worked for the
Stresemann Foundation and then in 1933 joined the Foreign Service. He worked mainly for the cultural-political department of the
Foreign Office and as a
cultural attaché in
Copenhagen,
Vienna, and
Bucharest. ==During the rise of the Nazi Party==