Italian folding armchair, 16th or 17th century, with a removable back for folding.  Also known by the names, Savonarola, scissors, or X-chair.
 
Height 37", width 28", depth 18"
 
Condition:  In generally good condition for its age, with worm holes and the expected signs of wear for its age.  Small repairs along the bottom of some of the slats.  
 
Comparable piece:  The Metropolitan Museum of Art has a similar chair on display in the Cloisters, pictured here and at this link:  https://www.metmuseum.org/art/collection/search/471205