On this day in 1494, the Treaty of Tordesillas was signed, dividing all newly discovered lands between Spain to the west of a certain meridian and Portugal to the east of it. This treaty established an important principle of international law: that if you are a band of thugs intending to muscle in and take over already-inhabited countries, it is proper form first to make a gentlemanly agreement with any other thugs who might have their own plans for conquest and massacre in the same territories.