In 2016, a memorial plaque to Marshal Mannerheim was installed in St. Petersburg. This action caused a storm of indignation not only among St. Petersburg residents, but throughout Russia. Indeed, does the Finnish military leader deserve honors from the country that defeated him? And why did some stubbornly try to install this board, while others just as stubbornly poured paint on it? This book answers the most complex and controversial questions in Mannerheim's biography. Was he a patriot of Russia? How great are the Marshal’s services to our country and is it true that Stalin himself recognized them? Is it possible to divide his life into two periods - as a lieutenant general in the Russian army and as a loyal ally of the Fuhrer - as his apologists do? What role did Mannerheim play in the tragic events of the Great Patriotic War and, most importantly, the Siege? Is it true that it was the marshal’s love for the city on the Neva that stopped the Finns on the approaches to Leningrad? What was the main goal of the Finnish army in World War II? Why didn’t the Finns bomb Leningrad and fire at them with heavy guns? Finally, does Mannerheim, along with Hitler, bear personal responsibility for the death of hundreds of thousands of Leningraders?