I've decided to start this topic, horrified by lack of historical knowledge by some KH players. Here, please post any tips or notes on the life of the middle ages and so on. I'll start this short glossary with:

Radar: an object-detection system which uses electromagnetic waves—specifically radio waves—to determine the range, altitude, direction, or speed of both moving and fixed objects such as aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. First working Radar 1904 - therefore not suitable for our RP

Coffee: A brewed bavarage, made of a coffee plant, that was firstly introduced in XVth century, with the first notes of brewing it from Arabia.

Warsaw: A village founded in Mazovia in XIIIth century. Capital of Poland since 1815 A.D. Not existing at all in XIth century. In game, administrators placed the main Polish castle in Kaliskie, while by the year 1040 it should be in Malopolska (city of Krakow (Cracow)), but this is due to game balance. Correct would be then to address a Polish capital in game as to Kalisz or - acceptably - Krakow

King of Poland: An inheritable title, used in Poland by both male and female rulers. Due to the Polish mediaval law, "Queen" is not an inheritable title. In the meaning of the Polish law, "Queen" is just a wife to a King. Due to that, every RULING female on the Polish throne was referenced by the Polish and foreign diplomacy as the "King". Here is an example from the history: http://en.wikipedia.org/wiki/Jadwiga_of_Poland - She was crowned as Hedvig Rex Poloniæ (Rex is latin for King), not Regina (Queen in latin). The same applies to current ruler of Poland in game - King Maria.

A note to Abel: If they don't teach you history of Poland in Dutch school, then on what basis do you try to teach a Polish person history of his own nation? I don't know much about history of Netherlands, so I wouldn't dare to correct a native Dutchmen in matters of history of his or her nation (at least without closely checking it out on books or on the Internet)