Then in 1405 he designated his henchman Yao Guangxiao to lead the work and mobilized more than 2,000 intellectuals, many of whose handwriting was exquisite, to enlarge the canon.

As they occupied themselves with the compilation, all their worldly needs were looked after.

After the masterpiece was completed in 1408, the emperor was so delighted with what he read that he wrote a personal preface to it and named the collection The Great Canon of the Yongle Era.

However, few of his successors took much interest in the canon until Emperor Jiajing, who frequently had several volumes at hand and often cited the canon in court.

The night the Forbidden City caught fire in 1557 he was so concerned about the canon's fate that three times during the night he issued decrees calling for all to be done to save it.

In 1562 Emperor Jiajing finally made up his mind to have the canon transcribed. Those working on it included Zhang Juzheng, a reformer and one of the most famous prime ministers of the dynasty.

In addition to a group of top scholars, another 109 people joined in on the transcription work. In fonts and type size the transcripts were consistent with the original. To assure accuracy, each of the transcribers was allowed to write down only three pages a day. Their bylines were left at the end to ensure the lines of responsibility were clear.

It took them five years to finish the work.