|Enemies||Poland, Sweden, France|
Historically, Brandenburg was a quasi-independent country that later became the core of the unified German state. It contained the future German capital Berlin. Since 1618, both Brandenburg and Prussia, then known as Brandenburg-Prussia, were ruled by Hohenzollern dukes (later "kings in Prussia"--the title "king of Prussia" was prohibited to them). The Frankish Nuremberg, Ansbach and southern German Hohenzollern and the eastern European connections of Berlin and the prince-elector together were instrumental in the rise of that state.
Brandenburg is situated entirely within the territory of Germania as defined by Tacitus in AD 98. By AD 600 the first Slavic tribes were recorded as having arrived. In 948 Emperor Otto I (the Great) established German control over the now largely Slavic inhabitants of the area and founded the dioceses of Havelberg and Brandenburg. In the great uprising in 983 the Slavs ejected German control of the territory of present-day Brandenburg. The monasteries were razed, priests and Germanic officials killed or expelled. The Slavic tribes living east of Elbe remained independent and pagan for the next 150 years.
In 1134, in the wake of a German crusade against the Wends, the German magnate Albert the Bear was granted the Northern March by the Holy Roman Emperor Lothar II. Many Slavic groups survived the conquests and live there still today, e.g., the Sorbs, Wends and Lusatians. The Roman Catholic church brought bishoprics to the new walled towns, which afforded protection for the burghers from attack. With the monks and bishops, the history of the town, later the state, of Brandenburg began.
Albert's control of the region was nominal for several decades, but he engaged in a variety of campaigns against the Wends, as well as more diplomatic efforts that saw his control become more real by the middle of the century. In 1150, he formally inherited Brandenburg from its last Wendish ruler, Pribislav. Albert and his descendants, the Ascanians, then had considerable success Christianizing and cultivating the lands. There was never any "racial" distinction made by the German rulers and the Slavic and German tribes freely intermarried.
In 1320 the Brandenburg Ascanian line came to an end, and from 1323 until 1373 Brandenburg was under the control of the Wittelsbach family, also rulers of Bavaria. This was followed by a period of rule by the Imperial Luxembourg dynasty until the margravate was granted 1415 by the Emperor Sigismund to the house of Hohenzollern, which would rule until the end of World War I. From 1356 until the Empire's end in 1806, the Margrave of Brandenburg was also one of the electors of the Holy Roman Empire.
Brandenburg was one of the German states to switch 1539 to Protestantism in the wake of the Reformation, and generally did quite well in the century following, as the dynasty expanded its lands to include the Duchy of Prussia in 1618 and along the lower Rhine Cleves (1614) and elsewhere. The result was a sprawling, disconnected country that was in poor shape to defend itself during the Thirty Years' War.
Towards the end of that devastating conflict and after, however, Brandenburg (and its successor states) enjoyed a string of talented rulers who gradually maneuvered their country towards the heights of power in Europe. The first of these was Frederick William I, the so-called "Great Elector", who worked tirelessly to rebuild and consolidate the nation. He moved the capital from the town of Brandenburg to Potsdam.
When Frederick William died in 1688, he was followed by his son Frederick, third of that name in Brandenburg. As the lands that had been acquired in Prussia were outside the formal boundaries of the Holy Roman Empire, Frederick assumed (as Frederick I) the title of "King in Prussia" (1701), basing this promotion from margrave on his title to what were, in actuality, vast but less agriculturally valuable stretches of sandy ground. Brandenburg was still the most important portion of the kingdom (and the state was often referred to informally as Brandenburg-Prussia) but for the purposes of accuracy, the continuation of this history can be found at Prussia.
True power of Brandenburg reveals shortly after transforming to Prussia. If you are a novice player, it is strongly advised for you not to start unification of Germany before 1550s. Remember, that being both military and ecomonical superior, you get huge bonuses to diploannexations. Try to establish an alliance with as many German minors as you can, and then diplovassalize and diploannex them one by one. Brandenburg/Prussia, being in the center of Europe, has many wars with various enemies. Don't be afraid to engage in the conflicts that will help in keeping Germany neutral - if you manage to keep German states independent, you will have a lot of opportunities to annex them later and create inland empire. Also, as a Emperor with boatloads of allies, you get huge manpower bonus that lets you easily overrun enemies. Your areas of expansion are: Germany, Baltic, Netherlands, Denmark.
Domestic policy sliders
Full Aristocracy - helpful in making a lot of cavalry, and diplomacy bonus
Full Centralization - every country wants full centralization except those trying WC
Rather Innovative - bonuses that comes with innovativness are cool, but you should always have at least one missionary,
Rather Offensive - you have some bonuses, but try to keep the cost of fortresses low,
Full Land - you are neither a naval nor colonial power,
Full Quality - many wars means you have to have elite troops,
Rather Serfdom - low infrantry cost and a moral boost are important, but in the late game (after the unification) you will have a lot of problems with stability.
Start a massive alliance with four minors. Diploannex one of them and then invite some other minor to it. Diploannex another etc. until you swallow the whole of Germany. At higher difficulty levels, Badboy increase will require patience.
The second option is waiting for two major alliances to form - one with you, Brandenburg. DoW the second alliance and annex them all. Do the same with the next alliance, etc. until you swallow all of Germany. Countries in western Germany tend to form really powerful alliances - Kleves, Pfalz are the most powerful nations from that region. DoWing Württemberg, Würzburg or Bavaria may make Austria declare war on you as well, as it often guarantees them independence.
Also, you can ally with a country outside Germany and then DoW all the minors. It may, however, cause Germany to fall into two pieces - one Prussian and the other belonging to your ally. It may also lead to wars with a powerful opponent in the future. Furthermore, Austria may be hostile after seeing your expansionism, and if the Burgundy inheritance event happened, they can invade you from two directions.
Killing them all
This one is particularly tough on hard+, so it is adviseable only for experienced warmongers. It is about force-annexing all the minors from the very beginning - declaring war, annexing one, force vassalizing the others, inviting them to the alliance, warring another few minors, diploannexing allies, inviting new vassals to the alliance, etc. It is especially troublesome when you are being attacked from various directions. Also, if you are dowed by the alliance just after dealing with the previous one, your badboy will go skyhigh and you will suffer from badboy wars.
That's when the true fun begins - you must fight for the supremacy in Europe. It means warfare Poland, Austria and Sweden all the time. Just remember not to engage in more than one war at the same time. Build some ships, so that you could invade the colonial possessions of your enemies. These are things you have to remember.
For the Prussian player, the perfect situation in the Scandinavian Peninsula is a perfect balance of power. It would be best if all three nations (Denmark, Sweden and Norway) existed, all in equal strength. It can be hard to maintain, especially if you have no fleet. The situation with only Denmark and Sweden is also good - always ally with the weaker one and support it in the wars with the stronger one. If you do it well and establish the balance between the power of the two nations, Sweden will be too weak to attack Baltic countries and Denmark too weak to attack your northern borders.
Poland probably has the worst position in Europe -- between the four superpowers, Russia, Sweden, Prussia and Austria. As Prussia, you can DoW Poland when you want, but keep in mind that you have to keep Russia away from your borders as well. If Russians joins and gangbangs Poland with you, maybe you will share the common border at some time, which is very bad, because in late-game the Tsar is really warmongerish and can easily overrun you with numbers. Remember, rule #1 of War Club is 'Never start a land war with Russia'.
Until you unite ALL the German nations (including Württemberg, Lorraine, Strassburg, Kleves, etc.) you probably won't have a common border with France. Just try to keep them away from German provinces and build up the fortifications - it will be very helpful, when Napoleon comes. You can fight with them for Luxembourgh, and rich norh-eastern provinces (Artois, e.g.).
Remember, between approximately 1520 and 1700 Austria hates you because you are Protestant and after the Edict of Tolerance (approx. 1650), because you can overrun Germany. Never, ever ally with them and try to weaken them all the time. Try to gang up on them with Ottomans or Russia. Your priority is to acquire provinces with German culture - Tirol, Ostmarch etc. You can also grab Bohemia, but those provinces are very warscore-costly and you will need at least a few wars.
Late-game is a period many experienced players (but not all, by any stretch of the imagination) cannot endure due to perceived tedium. If you want to have competition in late-game and enjoy difficulties till 1819, remember not to vassalize any of your neighbours (even if they are utterly destroyed) and don't take more than two provinces in each war during the game. Really. Oh, and don't invest in infra after level six - it spoils SP completely. See SP Rythin's rules.
For experienced players
Unify Germany as soon as possible (preferably before 1550s) and then conquer Europe ;-) I did my first WC with BB/Prussia (after some point I changed the TAG to Germany) and I must say it was rather easy (AFAIR I used some event boosts - when nationalism had died out, I added the province as a core, a bit gamey).
Prussia in AoI
Hive's Age of Imperialism covers the period between 1337 and 1913. And I must say that playing Prussia in the late 18 cent. and 19 cent. is extremely enjoyable. There are a lot of cool events, historical leaders and other amusing features. The later scenario you pick (1861 would be the best, IMO), the more fun you will have.