The following article was sourced from a Wikipedia page at the following address: http://en.wikipedia.org/wiki/Henley_shirt
They were so named because this particular style of shirt was the traditional uniform of rowers in the English town of Henley-on-Thames. Some crews still use this style as part of their uniform.
Originally quite popular in the early 1970s, Henley shirts have recently made a fashion comeback, especially in Western countries such as the United Kingdom, United States, Canada, and Australia, but also in some East Asian countries such as Japan and Korea.
In his biography of Ralph Lauren, the journalist Michael Gross quotes a New York merchant who recalled showing a vintage shirt to a Ralph Lauren buyer: "I showed this fellow underwear—a three-button long-sleeve shirt by Johnstown Knitting Mills. He said, 'This is a new shirt.' That's where he got the idea for the Henley shirt."
To read more about Henley shirts, please click on the following link: http://en.wikipedia.org/wiki/Henley_shirt