Charles Nissen (1880 - 1944) was one of the most industrious and dynamic men of philately, best remembered for unearthing a major postage stamp fraud.

British born Nissen was instrumental in building the Royal Philatelic Collection of the royal family, regarded as one of the greatest stamp collections in the Commonwealth. Often acting as philatelic adviser to King George V, Nissen was granted a Royal Warrant for his efforts.

Nissen was a well-respected stamp dealer, handling many notable specimens in his lifetime. His company, Chas. Nissen & Co. Limited, continued to thrive long after his death and was granted a Royal Warrant from Elizabeth II.

Nissen had made an early impact on the philately world when in 1898, at the age of 18, he discovered what became known as the Stock Exchange Forgery. Nissen found that a number of used stamps on telegraph forms from 1872 and 1873 lacked watermarks and had unusual corner lettering.

It was subsequently revealed that a Stock Exchange Post Office clerk in London had been pocketing one shilling telegram fees while using forged stamps. Following fruitless Police inquiries, it was presumed that the culprit had died in the intervening years. The faked stamps often appear at auction and can command significant prices.

Nissen wrote The Plating of the Penny Black Postage Stamp of Great Britain, 1840

A distinguished author on philately, Nissen's seminal work is The Plating of the Penny Black Postage Stamp of Great Britain, 1840, which he published in conjunction with Bertram McGowan in 1922. Nissen subsequently received the Crawford Medal for philatelic literature from the Royal Philatelic Society London.

He also published the Official Stamps of Great Britain book in 1906, established the British Philatelist publication in 1908 and edited the Stamp Collectors' Annual with PC Bishop from 1904 to 1911.