I'm going to nominate three books.
Sappho's Poetry. Sappho was an acclaimed Greek poet who lived around 600 B.C. During her lifetime, her works about love and longing were considered masterpieces. Their content, though, had a definite woman-to-woman element that was later found objectionable by the Church. Christians began destroying her works in the 5th century A.D., and her poetry was officially banned by Pope Gregory VII in 1073. The destruction was so thorough that only one complete poem survived for many centuries until a cache of papyri, discovered in the 1800s, that had been used to wrap mummies and stuff sacred animals was found to include her writings.
Available at
Delphi Classics in epub and Kindle for $1.99.
Andersen's Fairy Tales. In 1835 Tsarist Russia, under Nicholas I banned the sale of
Andersen's Fairy Tales lest the violent nature disturb impressionable children. The ban remained in place until 1849. The stories were again banned in Soviet Union beginning in the 1930s because they glorified princes and princesses.
Available here
at MR in LRF.
A Farewell to Arms. In 1929, Italy banned Ernest Hemingway's
A Farewell to Arms for its vivid description of the Italian Army's disgraceful retreat following the Battle of Caporetto during World War I.
Available at
Amazon and
Kobo and
B&N for purchase. Hemingway is in the public domain in life + 50 countries, but I'll leave it to those fortunates to find a free copy.