The most notable group called chalkaspides was the main phalanx force of the Antigonid Macedonian army in the Hellenistic period.
The leukaspides may have been very similar to the chalkaspides and also fought as a phalanx, or they might be a term for non-Macedonian allies and mercenaries who used wooden thyreos shields rather than the bronze pelta.
[1] King Antigonus Doson armed the citizens of Megalopolis as "Bronze Shields" for the Sellasia campaign in 222 BC.
Plutarch records 1,200 wagons filled with bronze shields taken as spoils after the Roman victory at the Battle of Pydna in 168 BC, presumably from the defeated chalkaspides.
Plutarch writes of Mithridates VI of Pontus fielding a corps of chalkaspides against Sulla at the Battle of Chaeronea (86 BCE).