The BBC reported that prosecutors claimed Calislar had insulted Ataturk in a biography of Ataturk's wife Latife, in which Calislar reportedly wrote that Ataturk had once fled disguised as a woman.
Calislar faced up to four years in prison for violating Turkey's law against denigrating "Turkishness."
The European Union has put pressure on Turkey to rescind the law, saying it is an encroachment on freedom of expression.
The law reportedly has landed dozens of writers and journalists in hot water, including novelist Orhan Pamuk, the 2006 Nobel laureate for literature.
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