Genoa being a maritime province was inhabited by many sailors. The Genoese Navy wanted trousers for sailors that would be hardy enough for them to do their duties which included the scrubbing of decks. The hardiness of denim satisfied this need. That was the birth of jeans.
Jeans were first hard wearing trousers for workers in factories. Initially mens jeans were identified by having the zipper down the front whereas the women had a side opening. Mens jeans were earlier loose fitting trousers but has since then been made into various styles including slim fitting jeans.
James Dean wore jeans in the film "Rebel without a Cause" and since then jeans has been on the road to fame.
Some styles of mens jeans are boot cut, slim, straight, skinny and classic. The various styles and the quality of denim determine what mens jeans should be worn to which function. Jeans are versatile in function and the most fastidious men should be satisfied that their purchase of mens jeans satisfies their requirements.
Some of the points to consider are whether the workplace allows casual clothing or not. In an environment that is formal, jeans will not be allowed and so the mens jeans purchased will be for casual wear and as such should be comfortable. If jeans are allowed then the mens jeans should have both comfort and style. Comfort because it is to be worn all day and style because it cannot be too casual.
The best pair of mens jeans should be timeless and the heavy investment should ensure good usage over a long period of time. Original blue jeans, dark slim jeans and slightly faded blue. They should also be of good fit. The waist, crotch and leg areas are the determining factor. There should be pocket space for keys, wallet and maybe a cell phone. Shoes should be worn when purchasing the jeans, if not, they will tend to look short when worn with shoes and will be very unsightly.
Jeans never really do go out of style. Jeans teamed with a well cut shirt and stylish sneakers or dress shoes makes for a complete and stylish look.