Livy wrote this History of Rome. Book 42 follows quieter years of fighting in the northern foothills and in Spain, and of colonies planted to hold the land. Rome was a republic, run by a senate and elected officials, not a king. Perseus of Macedon was already gathering strength.

Eumenes, king of Pergamum in western Turkey, brings the Senate a file: Perseus is rebuilding Macedon, courting the Greeks, and will not stay small. Rome declares the Third Macedonian War. Early fighting stalls. The phalanx, a wall of long spears, still works, and Macedonian forts still stand. Greek cities split over which power to endure. Charges of broken treaties fly both ways while citizen soldiers sail east. Livy looks toward a later battle at Pydna, but first he shows the slow start of a coalition war. A king who looked restorable is about to be erased.