Weapons and tactics of the Roman army in the era of the great wars with Carthage, Macedonia and the Seleucid Empire, as well as in campaigns against the Celts and the tribes of Iberian Peninsula, waged in the years 264–133 BC, are the subject of many publications. Earlier periods in the development of Roman weapons and fighting techniques have been comparatively neglected. The main reason for this is the low reliability of literary sources (Small 2000, p. 230) and almost complete lack of archaeological finds, the context and dating of which can be linked with the army of Rome in the period of the Early Republic (Rawlings 2007, p. 54), as well as the scarcity of iconographic sources. However, this period was crucial for the emergence of a particular method of fighting of the army, which was to conquer the whole Mediterranean world.

The aim of this text is to explain and interpret different types of sources and, as a result, to offer a reconstruction of major elements in the evolution of weapons and tactics of heavy infantry, which formed the backbone of the Roman army in the period when these changes occurred, with a special emphasis placed on the
widespread use of oblong shield and heavy javelin in the 4th century BC.