The territory's mineral wealth made it an important strategic region during the early metal ages, and one of the first objectives of the Romans when invading the peninsula was to access the mines and other resources. After the Second Punic War, from 29 BC to 411 AD, Rome governed the Iberian peninsula, expanding and diversifying the economy, and extending trade with the Roman Empire. Indigenous peoples paid tribute to Rome through an intricate web of alliances and allegiances. The economy experienced a major production expansion, profiting from some of the best agricultural lands under Roman hegemony and fueled by roads, trade routes, and the minting of coins, which eased commercial transactions. Lusitania developed, driven by an intensive mining industry; fields explored included the Aljustrel mines (Vipasca), São Domingos, and Riotinto in the Iberian Pyrite Belt, which extended to Seville, and contained copper, silver, and gold. All mines belonged to the Roman Senate, and were operated by slaves.