martti henrikki haavio (22 january 1899 – 4 february 1973) was a finnish poet, folklorist and mythologist, writing poetry under the pen name p. mustapää. he was born on 22 january 1899 in temmes, and died 4 february 1973 in helsinki. he was also a professor of folklore and an influential researcher of finnish mythology. in 1960, haavio married aale tynni, after his first wife died in 1951 of cancer. his daughter, elina haavio-mannila, is a social scientist. during haavio's early career, he was a member of the tulenkantajat literature club.