Letts was an English stationer and printer who popularised the diary. In 1816, his father published “Letts’s diary or bills owed book and almanack” as the first commercially produced diary, which Thomas developed into of dozens of differently printed and bound, annual publications. Thomas was joined in the family business by his son, Charles, and together they raised capital for expansion into a limited company in 1870, trading as ‘Letts, Son & Co.’ However Thomas died soon afterwards, being buried in West Norwood Cemetery in a Grade II listed monument. Charles reformed the company privately as Charles Letts & Co., trading profitably for the next century.