This is two short works by the Historian Tacitus. The Agricola is a biography of Tacitus' father in law and mostly focuses on his time campaigning in Britain. The Germania is not really so much history as a description of the ways of the people of Germany. Both works are minor, albeit fascinating. Tacitus is a good candidate for the second best of the ancient historians (after Thucydides) and his prose is great and his clever asides brilliant. The work is very enjoyable. There is good insight into the Germans for a Roman author, although one is always frustrated in that the Romans view other cultures so much through the lens of a military threat. That is not so bad here, but that is entirely the way that he sees the ancient Britains and nothing of there culture really comes through.
It is his various observations on this and that, so many of which are liftable straight out of his works and applicable anywhere. For instance, buried within a passage in the Agricola, he notes in passing that it is a part of human nature to hate someone that you have wronged. That's smart and he is full of that sort of thing. He is also a very good writer. Having said all that, these are still minor works, and not nearly as important as the Annals (I haven't read The Histories yet).