If not as old as sitting, chairs date back to at least 2980BC to 2475BC. Variations on the theme are innumerable and it would be easy enough to list 250 or more names of the various types.
We take the various chairs we have in our home for granted, yet 500 years ago, only the nobility and the clergy enjoyed the privilege of sitting down on a chair to eat or hold conversations. The rest of the population sat on boxes, or even the section of a log. By the 1500's the stool was commonplace, and by the 1600's it had acquired a panel back and in some instances, open arms.
Throughout Europe wealth increased and spread during the 1700's, creating a demand for more comfortable furniture on which to spend longer hours of leisure. Reflecting this, fully upholstered seats and shaped backs begun to appear and as most people could afford chairs, they started to be made in sets, in the early part of the 1700's, many were constructed in walnut and have not survived the ravages of woodworm, but the great quantity of mahogany chairs that were made from 1740 onwards have often survived in good condition and are still widely available.
By the 1800's, the chair was catering for every specialist need. Invalid chairs were an innovation, as were chairs designed especially for writing at a desk. Reading chairs had book rests attached for quite hours in the study, but these have rarely survived in their original condition, and low nursing chairs catered to the needs of those nursing small babies. In the United States, rocking chairs became very popular.