source : http://www.pourlemerite.org/
8 May 1667 - Order of Generosité established.
9 June 1740 - Renamed and established as the Pour le Mérite by Friedrich II.
18 January 1810 - Order Pour le Mérite reserved as a military order.
THE MEDAL CHANGES THRU THE YEARS
Over three hundred years ago, in the Germanic principality of Brandenburg, the Ordre de la Generosité was founded by the electoral prince, Friedrich Wilhelm. This was a secular military and civil order that was created for the purpose of rewarding loyal subjects for their outstanding service. The Ordre de la Generosité was not the first of the Prussian orders to be created. An earlier one, Order of the Swan, had been created in 1443, but did not survive very long. Unlike the Order of the Swan, the Ordre de la Generosité would grow with it's homeland which was the regions of Brandenburg and Prussia.
The medallion of the Order of the Pour le Mérite has had many alterations throughout the years, some of them rather subtle while others very dramatic. The basic design is that of a Maltese Cross with eagles with upswept wings between the cross arms. The Maltese Cross is an eight-pointed cross that was originally created as a symbol of the Order of St. John of Jerusalem, also known as the Order of Malta. The Order of St. John is a Roman Catholic Order of knighthood that was founded in 1066.
During the 1300's an order called the Johanniter Order was established and they used a medallion much like that of the Knights of Malta in that it was a white enameled Maltese Cross with crowned gold eagles, enameled black between the arms. It was worn from a black ribbon. This particular symbol of the Johanniter Order appears to have been the basis for many other designs throughout Brandenburg and Prussia.
When the Ordre de la Generosité was founded on May 12, 1667, it was beleived to be a simple gold cross with a precious stone in the middle. Then years later in 1685 the medallion for the order took on a new look that was much like Johanniter Order's medallion. This can be seen in the photos of both medals.
The new insigna comprised of a golden Maltese Cross, sky blue enamel, the uppermost arm bearing a handpainted golden letter "F", which stood for Friedrich, and was surmounted by a painted electoral crown. The other three arms had the words Gene, Rosi, and Te on them. The reverse of the medal was a plain blue enamel. The cross was worn around the neck from a long black, "watered ribbon" that was about "two fingers wide".
The design was revised in 1740 with the establishment of the Order Pour le Mérite. The obvious changes were that the words were changed to reflict the orders new name and silver stripes were added to the black ribbon. If a member of the Ordre de la Generosité received the Pour le Mérite, they would be required to return the older medal otherwise they kept the medal until their death.
A common question about the Order and the medal is why would a "Germanic" knight order in the kingdoms of Prussia and Brandenburg have a an order with French names. The answer to that question is that during the conceptions of both the Ordre de la Generosité and the Orden Pour le Mérite, the favored court language was French. It was the "cool" thing to do. It was very fashionable to speak French at the royal courts.
According to David Edkins the author of "The Prussian Order Pour le Mérite, History of the Blue Max" the medal went through many inconsistencies in appearance and construction during the time between 1740 and the 1800's. Eventually the style of type for the words changed from a script style to the Roman lettering style. The author goes into detail about these changes. There also were many variations during the later years and during World War I. He also discusses the variations that appear between the different jewelers that created the medals; Wagner, Rothe, and Godet.
It also should be known that this military award can only be given out by the reigning monarch of Prussia. Currently, there is no reigning monarch in Prussia, so any awards or awards that look like the Pour le Mérite after Kaiser Wilhlem II's abdication are not legitimate awards of the Order. This question has come up concerning awards that looked similar during World War II, but those awards were not the famed "Blue Max" (Pour le Mérite). The only Pour le Mérite award that is still legally and officially given is the Arts & Science award established by Koenig (King) Friedrich Wilhelm IV on 31 May 1842. The continuation of this award would require written approval by the heir apparant of the royal house of Prussia. If you wish more information concerning the "Peace Class" or "Arts and Science" section of of the Order of Pour le Mérite, please visit their website.