The pride of Ireland, Guinness beer, is known and loved by beer drinkers from one hundred and fifty countries of the world where it is sold. This dry Irish stout was created by the legendary master brewer Arthur Guinness in 1759, and its fame does not fade even after more than two and a half centuries. And for more than a century and a half, the label on beer bottles has been embellished by the harp, which is also a symbol of the Irish state.
The harp has been on the Guinness label since 1862 and is older than the Irish government. The Guinness Harp is based on a 14th-century Irish harp, known as the O’Neill Harp, or Brian Bora, which is kept in the Trinity College Library in Dublin. As an official symbol of the Republic of Ireland, it is on the coins of the national currency. At least it was, until the euro was introduced. During the Easter Uprising of 1916, the harp was also on the Irish flag.
Interestingly, the Guinness Harp is not only older, but also stronger than the government. These two harps are different - here's why: Guinness officially protected the appearance of the harp used on the label in the patent office in 1876, so the Irish government had to turn the state symbol to the other side, to distinguish it from Guinness trademark. Thus, while the Guinness harp always has a straight edge on the left, the harp on state insignia has a straight edge on the right.
The harp is one of the three elements that make up the distinctive Guinness beer logo - the other two are the word Guinness and the famous signature of Arthur Guinness. Over time, the visual identity of the logo has changed many times, and yet mostly only slightly. The harp was stylized and the font used to spell the word Guinness changed. The current one has been used since 2005.
These changes were published by the VinePair portal on this interesting infographic.