What strategy helped Romans succesfully conquer their neighbors?

Answer 1

Rome's conquest of her immediate neighbours was through straight military victory or victory in conjunction with alliances with other Latin cities. These alliances were made 3 times. The subjugation of the wider neighbours of the far larger area of central and southern Italy was more complex and the used strategies were:

1) Incorporation of many Latin cities into the republic with full citizenship and of the Volsci of the plains southern Latium and the Campanians north of Naples as partial citizens (without the right to vote) + the reestabishment of the alliance with the Hernici of the hills of southern Latium. This gave Rome extra manpower in the 2nd Samnite War

2) Establishing alliances with the Sabellians of cetnral Italy (Abruzzo region) and some Apulian cities. This gave further extra manpower for the 3rd Samnite War and semi-encircled the Samnites

3) Forcing the vanquished peoples (Samnites, Umbrians and Senoni Gauls) into alliances, rather than annexing them. This decreased the chance of rebellion.

4) Allowing allies to share war booty. This gave them an incentive to fight with Rome. The alliances were military and the allies had to supply troops at their own expenses. Thus, this incentive was crucial.

5) Annexing a strip of central Italy (southern Umbria and northern Abruzzo) from, coast to coast. This gave Rome better control over these regions and the Marche region.

6) Establishing Latin colonies (settlements) in strategic areas to have strongholds and a population presence (the colonies played a big part in the Latinisation of the vanquished people). The land confiscations that this required was also part of this social engineering.

7) Large scale enslavement after winning a battle helped to weaken the enemy.

After the Samnite Wars the allies supplied 60% of Rome's troops. In the 3rd century BC the allies alone could supply up to 350,000 troops.