Why do so many say king size?

Because these are sold to be slept in. One in three titles contains the word "king", and size language dominates the headings ahead of timber or period. Widening is common practice in the trade. Frames made for narrower French mattresses are re-sized with new side rails to take a 5ft king or a 6ft super king.

What period do most of them date from?

The dated field spans 1800 to 1930. Two decades carry more than half the archive between them: 297 listings dated to the 1900s and 285 to the 1920s, with 143 in the 1910s. Nineteenth-century beds appear too, some given a precise decade, others labelled simply "19th Century", "Victorian" or "Edwardian". Those are period words, so read them as approximations.

Are these beds always wooden?

No. Brass appears in 100 titles and iron in 86, and the two often turn up together in one frame. Wooden frames still dominate, in walnut, mahogany, oak and painted finishes, and upholstery is described in a sizeable minority of listings.

What does corbeille mean on a bed?

A curved, basket-shaped head and foot. Thirty-three titles use it, and some say demi-corbeille where only one end takes the shape. It usually comes with upholstery. Corbeille frames sit within the padded-panel branch rather than the caned or iron ones.

Do these beds come with a mattress or base?

Often not. "Bedstead" means head, foot and side rails as a frame, and 20 titles use the term. Some listings do add a base, and those tend to sit higher in the range, as do beds sold with matching bedside cabinets or as part of a bedroom suite.

How many turn up for sale each year?

About 82 French beds are listed on Sellingantiques in a year. A hundred different dealers have handled one, so almost every dealer who carries them carries only a handful at a time.