The legacy of A Dream of the Red Mansions (also known as "Dream of the Red Chamber") takes another important turn some 250 years after the great classic was written.

The first English-language book about the novel's mysterious author Cao Xueqin has been published by US company Peter Lang.

Between Noble and Humble: Cao Xueqin and the Dream of the Red Chamber took American scholars Ronald Gray and Mark Ferrara nearly five years to translate from renowned Chinese scholar Zhou Ruchang's New Biography of Cao Xueqin.

The translators and Zhou discovered a precious English translation based on a previously unknown Chinese version of the novel, which sheds new light on the study of the classic, which is known as hongxue, or "redology".

Gray first met Zhou in 2002 when the Chinese scholar gave two English-language lectures to foreigners in Beijing. Gray had just read the Qing Dynasty (1644-1911) novel translated by Yang Xianyi and his British wife Gladys Taylor.

He was "overwhelmed" by the story, which he calls "engaging, surprisingly accessible and ultimately enchanting". Gray strongly agrees with Zhou that reading the novel is "the most enjoyable and interesting way for Westerners to learn about traditional Chinese culture".

At Zhou's suggestion, Gray and Ferrara began translating the biography of Cao Xueqin (1715-64) in 2004. Gray read different translations of Cao's novel more than 10 times and consulted many experts.

They made a breakthrough discovery along the way. A few years ago, Hong Kong University posted online a manuscript by Dr B.B. Bonsall, a British missionary in China from 1911-1926.

Gray found that Bonsall was the first Westerner to translate all of the novel's 120 chapters into English in the 1950s. Zhou confirms the discovery's value, as the unpublished manuscript was based on a Chinese version different from any known editions.

This year, Yang Xianyi and British Sinologist David Hawkes, both best known for their complete translations of the novel, passed away.

"The multitude of translations of the classic proves its importance and greatness," Zhou, 91, says in an e-mail.

"One might have to wait many years before better translations could come out." But the publication of Cao Xueqin's biography in English helps compensate.

"In the 245 years since Cao Xueqin passed away, this is the first English-language biography that introduces this author to the global literary circle," Zhou says.

As more scholars and readers acknowledge the novel's strong "autobiographical character", they realize that reading the classic alone cannot provide a comprehensive understanding of its background, formed by the author's family, society and history.

"This translation has extensive and important meaning for cultural communication between China and the West," Zhou says.

Gray, who taught in Chinese universities for more than eight years and published several papers on the novel, says the biography "should fill a big gap" in Western redology.

While most Western scholars have analyzed the novel as a work of fiction and shied away from its autobiographical elements or its author, "Zhou does an excellent job of historically situating Cao and his family", Gray says.

"I view Zhou Ruchang as my teacher (in both the Confucian and academic sense)," says Gray, who has visited Zhou's home 12 times. "I have learned so much from him about the novel and Chinese culture, and greatly admire his long and heartfelt devotion to the novel."

Ferrara, who taught writing and literature at Fudan University in Shanghai, met Zhou in 2005. "I marveled at the range of his intellectual curiosity, his sense of humor and his continued enthusiasm about Honglou Meng. He was very warm and welcoming, and he does care for small talk," he says in an e-mail.

"He (Gray) is a philosopher. Our discussions usually focused on Cao Xueqin and Zhuangzi (an ancient Taoist philosopher)," Zhou says.

"I am both surprised and moved by the great efforts the translators have made. The English translation is of superb quality."