Russian film stars, a cosmonaut and French actress Fanny Ardant are among 1,300 people reading Leo Tolstoy's epic War and Peace live on the internet - a 60-hour marathon spread over four days.
The event was organised by Russian state broadcasters and it is being streamed online.
Places that feature in the novel were chosen as settings for some chapters, including the Borodino battlefield, where in 1812 Napoleon's troops fought the Russians.
War and Peace was published in 1869.
The novel - one of Russia's greatest works of literature - follows the lives of aristocratic Russian families during the French invasion in the early 19th Century.
Readers include schoolchildren, sports personalities, scientists and armed forces staff.
Cosmonaut Sergei Volkov is joining in from aboard the International Space Station.
Count Tolstoy's former home at Yasnaya Polyana is one of the venues - where Vladimir Tolstoy, a great-great-grandson of the writer, will take part in the reading. The estate is about 200km (124 miles) south of Moscow.
The scale of the book reading "has no parallel in the whole world", say organisers at the website voinaimir.com.
"The geography of the project is immense - from Kaliningrad to Kamchatka, from Franz Josef Land [in the Arctic] to London and Paris," they say.