China's contribution to victory in World War II is "huge", said Robert Frank, secretary-general of the 22nd International Congress of Historical Sciences on Thursday at Jinan, Shandong province.

"It was also a very difficult contribution. ... That China emerged victorious proves that it was a great factor in the world war," said Frank, who is also a French historian.

China had been weak since the mid-19th century's Opium Wars, Frank said. But after the United Nations was established in 1945, the country received one of the five permanent seats on the Security Council. Ten other seats rotate among UN member states.

"That means other powers were aware that China played a central role in the war. It can be seen as a recognition of China's standing in the war," Frank said.

Historians fix 1937 as the start of World War II in China, but the date could be placed earlier, Frank said.

"The date could be considered as early as 1931, when the Japanese attacked Manchuria in Northeast China," he said. "We can see easily that the war began in Asia. We chose the date 1937 because the gunbattle at the Marco Polo Bridge (known in China as Lugou Bridge) started the general war between Japan and China."

"China is the first victim because China was the first country invaded. It means China had the first movements of resistance against occupation," he said.

"They are not accustomed to this date. In Europe, people are used to saying the war began in 1939, because in Europe the war began in 1939."

Frank took the book 1937-1947 World War, published in France in April, to the Jinan congress, which concluded last week. He was editor-in-chief of the book, a compilation of accounts from 40 historians.

The year 1947 was chosen as the formal end of the war, Frank said, because the first peace treaties with Germany's European allies were signed that year in Paris.

"The book deals not only with China and Asia. It includes the history of all the continents during that time of war. We wanted to write a global history of a global war and to break the classical Eurocentric chronology," Frank said.