This armor predates and certainly must have served in the English Civil Wars. It comprises six pieces, including its original gorget. It dates to the period of transition from lighter armor to shot proof. The breastplate is provided with lugs for the attachment of a reinforcing plate allowing flexibility to adapt from guard to combat mode. See item #2 following for a related reinforcing breastplate.
Backplate with makers marks RR with canted serifs, of Richard Rathbone who worked in London 1617-36, supplying the Tower.