The custom of including a rather unconventional ingredient when brewing beer is not exclusive to today’s brewing age, but rather it is something that has always existed and been considered an option by master brewers.
Adding other fermentable ingredients such as sugar has always been and remains commonplace in different beer brewing styles, particularly Belgian or English beer with a high alcohol content. The principle of adding sugar other than maltose, the main sugar in cereal in mashing, is to make the beer lighter while increasing its alcohol content.
If we bear in mind that honey is a natural ingredient containing around 80% of fermentable sugars (fructose and glucose), we could be led to believe that the original reason behind using it in brewing was to add more sugar to the must, thereby helping yeast with to metabolise.
We know that honey was used as an ingredient in beer brewing in ancient Egypt, and also that dates and other fruit were sometimes added. The Ancient Greeks also used honey, and it is furthermore likely that some of the beers that were widely consumed throughout the Roman Empire continued to use it. Nevertheless, in the following centuries brewing and drinking beer in Europe underwent a standardisation process, and honey was no longer a standard ingredient in beer.
Honey though, is not only a source of fermentable sugars in beer brewing, but depending on its flavour, it can confer special features to our drink. Acacia honey, for example, is more neutral and will reduce the body of our beer, whereas chestnut honey will make it darker and give it the characteristic flavour of honey. Because of its organoleptic properties, honey is still used in a few brewing recipes, which are grouped together under the name of Honey Beer, or in special brews designed for the winter or Christmas periods.

Finally, what used to be a peculiarity in some markets, such as the Anglo-Saxon market, is today more common in craft beer the world over. There are a few types of this beer in Spain such as Agente 99 by BeeBeer, or the Arevaka brewery in Soria with its “Negra con Miel” (Honey Stout). Some of the classical breweries such as Dupont in Belgium have recovered their former version of this beer style, known as Biere de Miel, first launched in 1922 and reintroduced back in the late 20th century. One of our biggest national breweries, Cervezas Alhambra, also have their own version of Honey Beer with some special editions such as Numerada de Miel y Romero.
Cheers!