No-one knows exactly when or where cheese was invented - although it can be said for certain that it was not in Switzerland. One story has it that a merchant travelling through the desert 5000 years ago made the discovery by accident when the milk he was transporting in a bag made of a sheep's stomach reacted with the natural rennet in the stomach lining and was churned into cheese by constant jogging. Be that as it may, cheese is certainly mentioned in the Old Testament in texts which may date back 3,500 years.
Swiss cheese was mentioned by the first century Roman historian Pliny the Elder, who called it Caseus Helveticus - the "cheese of the Helvetians", one of the tribes living in Switzerland at the time.
From cottage cheese to hard cheese
For centuries the standard type was cottage cheese, made by souring milk, and which did not keep. The technique of using rennet - a substance taken from the stomach lining of calves - to make hard cheese first appeared in Switzerland around the 15th century. Since such cheese could be stored for lengthy periods it is not surprising that it soon became part of the basic fare of travellers.
The monks who looked after the hospices at the top of some of the major passes, snowed in for part of the year, kept large stocks of it for their guests. And they needed to be large: one guest who passed through the hostel on the Great St Bernard pass was Napoleon, who - with the help of his 40,000 troops - got through a tonne and a half of the monks' cheese in May 1800. (The monks had to wait 50 years before they saw any money at all for it, and it was only in 1984 that the then French President, François Mitterrand, made a token payment of the rest.)
Cheese and cheese makers go abroad
Once it could be stored, Swiss cheese soon became a valuable trading commodity. By the 18th century it was being sold all over Europe - even to the detriment of the local market, if a 1793 travel guide is to be believed:
"It is rather strange that cheese and butter should be so bad in inns throughout Switzerland. Even in the regions which produce a lot of milk, it is hard to get good cream for your coffee or fresh butter, because the locals find it more profitable to make cheese out of their milk."
Switzerland soon exported not only cheese but cheesemakers too. Many of the thousands of Swiss emigrants who settled in the US in the 19th century were dairymen, some of whose descendents are still making cheese there today. Others were invited to Russia and eastern Europe to help set up a dairy industry. Some of them remained in those countries, but many eventually came back to Switzerland. It was Swiss cheesemakers who developed Tilsiter cheese, named after the town of Tilsit, which was then in East Prussia, and is now the Russian town of Sovetsk. They brought their new product back with them when they returned home. Even today, the Swiss government provides advice and practical help in cheesemaking as part of its aid to developing countries.
... and a pasture that went abroad too
Not quite such a success story as far as the Swiss were concerned was the accidental cession of valuable pasture land to Italy in 1821. A notary in Brig sold the Bettelmatt Alp, on the border between Switzerland and the Piedmont, to an Italian, without realising that it would thereby change country.
The pasture, sufficient for about 100 cows, is renowned for its juicy grass and aromatic herbs.
But the creamy cheese it produces is now an Italian, not a Swiss, variety.
From the comment of s.j.simon