The Agricola (Latin: De vita et moribus Iulii Agricolae) by Tacitus is a short biography of his father-in-law, the general Gnaeus Julius Agricola. This provides the occasion for an account of Britain and events there during Agricola's governorship. As in the Germania, a much more detailed ethnographic work, Tacitus' portrait of the barbarians is partly intended to throw into relief the decadence of Rome. The clearest example of this is the speech put into the mouth of the Caledonian chieftain, Calgacus, who says of the Romans that 'they make a desert and they call it peace.'
In the Agricola this contrast is given added point by Tacitus' attempt to show that provincial service could be a way to lead an honourable life in the face of the tyranny of Domitian portrayed in the concluding chapters of the work.
Internet Archive: The Agricola and Germania, translated by R.B. Townshend. Multiple formats.
Poetry in Translation: The Agricola and Germania, translated by A.S. Kline (2015). Multiple formats.
Wikisource: The Life and Death of Julius Agricola, translated by Alfred John Church and William Jackson Brodribb, 1876. Online, downloadable as PDF/MOBI/EPUB.
The Great conversation: further reading at Tom's Learning Notes.
Tacitus: The Annals.
Tacitus: The Histories.
Tacitus: The Germania.
Latin Resources: Online materials for learning Latin.