Lorica Segmentata

There were three basic types (Kalkriese, Corbridge, and Newstead) and one related form (Alba Iulia). Each cuirass was made up of four sections: two for the shoulders and two for either side of the torso.

It was first used at the end of the 1st century BC, and continued in service with the Roman army until the middle of the 3rd century AD. It is probably best known from the spiral reliefs on Trajan's Column in Rome (ITA) and it was sculptures of this type that first led scholars to study it... and in order to do so, they had to think of a name for it. Since most scholars at that time wrote in Latin, they coined the phrase lorica segmentata ('armour in pieces'). It is still known by that term, but you will also find it described as segmental, articulated, or plate armour, or even Schienenpanzer.

http://www.loricasegmentata.org/