Denis Vrain-Lucas was trained as a law clerk, but by 1854 he had begun to forge historical documents, especially letters. Lucas began by using writing material and self-made inks from the appropriate period and forged mainly documents from French authors. He collected historical details from the Imperial library. As his forgeries were more readily accepted, he began to produce letters from historical figures.
Over 16 years Vrain-Lucas forged total of 27,000 autographs, letters, and other documents from such luminaries as Mary Magdalene, Cleopatra, Judas Iscariot, Pontius Pilate, Joan of Arc, Cicero and Dante Alighieri - written in contemporary French and on watermarked paper. The most prominent French collectors bought them, helping Lucas accumulate a significant wealth of hundreds of thousands of francs.
In 1861 Vrain-Lucas approached French mathematician and collector Michel Chasles and sold him forged letters for Robert Boyle, Isaac Newton and Blaise Pascal. In one of them Pascal supposedly claimed that he had discovered the laws of gravity before Newton. Since this would have meant that a Frenchman would have discovered gravity before an Englishman, Chasles accepted the letter and asked for more. Lucas proceeded to sell him hundreds of letters from historical and biblical figures.
In 1867 Chasles approached the French Academy of Science, claiming to have proof that Pascal had discovered gravity before Newton. When he showed them the letters, scholars of the Academy noticed that the handwriting was very different compared to letters that were definitely by Pascal. Chasles defended the letters’ authenticity but was eventually forced to reveal that Vrain-Lucas had sold them to him. […] In February 1870, the Correctional Tribunal of Paris sentenced Vrain-Lucas to two years in prison for forgery. He also had pay a fine for 500 francs and all legal costs. Chasles received no restitution for all the money he had wasted on the Vrain-Lucas forgeries.