After considerable resistance from Lusitanian tribes in the 2nd-1st century BCE, the Romans gained a tentative foothold over the areas south of the Tagus and north of the Sierra Morena during the 130s BCE. While early encampments had been made in Cáceres from 139 BCE (Castra Servilia) and in Almourol (in the Tagus valley) from 138 BCE, Roman progress was only made in fits and starts. Lusitanian rebellions - notably the Sertorian War (80-72 BCE) - hampered progress, with effective Roman rule being achieved in the area under Julius Caesar's campaigns in 61-60 BCE.