The “Pound Sterling” is so named because its value originally equaled the price of one pound (unit of weight equivalent to about 12 ounces) of sterling silver. But why is the term “Pound” used in English? Because the term originally arose in Ancient Rome, where they used the Latin construction “Libra Pondo” to speak of coins (literally means “a pound of weight”). In Spanish we continue to use the term Libra, but in English that term was discarded and they were left with the “Pondo” or rather, its English evolution: Pound.
In the image above we can see the first symbols that represented the «Libra Pondo». On the left we can see how the hasty pen of the scribes could give rise to the horizontal line that joins the two letters. This horizontal line is maintained in the current version of the ‘pound sterling’, although only a stylized L is represented here: £.