Men's fragrances have evolved from a rare commodity into a billion-dollar industry

In the glorious days of ancient Rome, men very seldom bathed themselves in any kind of fragrance, unless as a vital sacred ritual and only rubbed on or poured on against ailments. Even the great philosopher Plato believed that smell could only be "defined relatively, in terms of other smells". But things have shifted. The whiff that accompanies a gentleman is not only a billion-dollar industry with extreme marketing budgets and celebrity endorsement, but also an artful caress of expression.

Smell is essentially primal and, according to Barbara Herman, author of "it penetrates the oldest part of the brain - the rhinencephalon - where the limbic system, or seat of our emotions and memories, resides". This goes a long way towards explaining why a whiff of certain foods sends us spiralling back to visions of our childhood, or why particularly intense perfumes, such as Versace's Oud Noir or Tom Ford's Café Rose, are unforgettable - whether or not you're a fan of the aroma.

British perfumer Roja Dove calls scent "the most profound of all the senses" as he believes that each odour stimulates the synapses located in the most primitive part of the brain, releasing hormones which govern every bodily action. "Scent works like a cat-burglar," he says. "It [intrudes] into our minds ... unlocking the floodgates to memory and emotion."

It comes as no surprise then that the world's biggest perfume retailers have capitalised on this particular phenomenon. Fashion houses are clearly keen to get a piece of the lucrative pie - even Bottega Veneta, ever cautious when it comes to new ventures, released its first male fragrance, Bottega Veneta Pour Homme, in stores in September last year.

Some brands are even offering fragrances that have been specifically designed for a particular market and background. Tom Ford's Sahara Noir, for example, with its notes of Levantine cypress, Jordanian calamus and bitter orange, was inspired by the concept of Arabian nights, and the fashion house targeted the Middle Eastern market accordingly. Sahara Noir was launched exclusively in the Middle East last April, before it was finally released worldwide later in the year.

Like with everything in life, the popularity of scent is cyclical. "In the 19th century a single-note floral scent was replaced by more abstract perfumery that included synthetic ingredients," Herman says. Thanks to perfumers like Paul Parquet, who created Fougère Royale by Houbigant in 1882, the fragrance world saw an increase in popularity of "dirty and erotic notes". This trend eventually dissipated, giving way to the cleaner scents of the 1990s, such as CK1 and CK Be.

Herman's observation also lends credence to the ever-shifting role of gender in perfume, that is to say whether a scent is masculine or feminine. Men wore more floral scents in the 19th century while women preferred cigar-like smells in the swinging art deco period, thanks to Guerlain's Shalimar and Millot's Crêpe De Chine, leading to a total reverse of roles in the current day and age.

On a more philosophical note, Herman observes, it touches on the fluidity of gender roles and how they are culturally constructed, and Chandler Burr, the former scent critic and host of scent dinners across the globe, agrees. "Smelling [womanly] or manly is a complete cultural fabrication and differs hugely from culture to culture and era to era," he says.

The fragrance Portrait of A Lady, for example, from the Frederic Malle collection, is described by Burr as "a gigantic rose so beautiful it brings you to tears". He reckons it is best on a man.

Choosing and properly wearing a fragrance, therefore, is no easy task. With all the bottled scents available on the market, the experience can be an overwhelming and oftentimes confusing one. The bottle design, the effects of advertising, the layers and notes of the fragrance, even the feeling of the perfume, can all affect how you feel about a certain scent.