Historically coffers were the general purpose storage units of their day, but also were used for seating (and even for sleeping upon). All had locks to ensure privacy; most members of the household had their own coffers for their own belongings.
Ours is a joined, 3 Paneled chest. In joined coffers, the panels are set into frames that allowed the wood to move, so they suffer less from shrinkage cracks. The outer stiles extend downward to form the legs.