Shilling is a purely Teutonic word, found in all languages of the Germanic group with appropriate spelling in each.
In English, it dates back to the Anglo-Saxon scilling, from there to the Gothic skilligs.
It has been adopted into most of the Romance languages, again with appropriate changes in spelling.
The root is uncertain, but seems probably to be skel-, “to divide.” It seems always to have been a unit of currency, and a subdivision of the major piece of currency of the country, e.g., in England, of the pound.
As for the pound itself, it was originally so-called because, in fact, it was a pound (Troy) of silver, though this has not now been true for many years.
But despite the purely Teutonic background of the shilling, but not of the pound, the abbreviations of both come from their Latin equivalents.
Thus the £, denoting the pound of money and the lb. indicating the pound of weight are both from the Latin libra, “pound,” while the s. for shilling is the abbreviation for the Latin solidus, a monetary unit equal to 25 denarii (from which comes the d. for pence).
The English abbreviation for shilling is sh. rather than s. In former times the abbreviation actually used for shilling was the long s.
Written quickly, this soon degenerated into nothing more than a slant line (/), and it is from this degeneration that the slant line has received the name, solidus, that it is now known by.