Composition:

-Most of Sweden
-Southern Finland
-Netherlands north of the Waal, including northern Rotterdam
-Germany less the Rhineland
-Northeastern Austria, north of the Danube, including northern Vienna
-Poland
-Czechia
-Most of Slovakia, including Bratislava
-Belarus
-Northwestern Ukraine, including Kiev at the border
-Small chunks of Romania and Moldova
-Estonia
-Latvia
-Lithuania
-Kaliningrad
-Northwestern Russia, including ex-Saint Petersburg

Neighbours:

-Northern Kingdom (Walter) to the north in Sweden/Finland/Russia

-Imperial Roman Republic (Snip) to the south in Netherlands/France/Switzerland (!)/Austria/Hungary

-Bzyantine Empire (Jefgte) to the southeast in Romania/Ukraine

-Mongol folks (NPC) to the east in Russia

Subdivisions

The Vilnius Union is divided into six political and economic regions that kind of, but don't completely, correlate with the Union's growth.

The largest region is the Rzeczpospolita, the core of which is the old Polish-Lithuanian Commonwealth that was the muscle behind the Union's initial formation; this is not a coincidence.  The Rzeczpospolita also includes bits of territory on the south and southeast that were acquired in recent conflicts with the Mongols.  21 IC, 9 BP.

To the north is Sverige, reduced to something of a rump state when old Sweden was lopped in half in the early 1700s.  The only non-rump element of Sweden to remain was Swedish Pomerania.  8 IC, 4 BP.

The rest of the ex-Swedish possessions, along with territory picked up from Rus and the Mongols, are amalgamated into Suomi.  7 IC and 2 BP; the area is not especially industrialized.

To the southwest of the Rzeczpospolita is Dunaj, formed from lands along the north bank of the Danube such as Austria, Bohemia, Bavariaand Wurttemberg.  It's an important economic area with 13 IC, 4 BP.

West of the Rzeczpospolita is Deutschland, consisting of old German kingdoms such as Prussia, Brandenburg, and Saxony, to the degree that the Union could make sense of the unholy geography of the Holy Roman Empire.  Given Deutschland's enclaves in both Rzeczpospolita and Nordsoen, and the inclusion of large ethnic German territories in Nordsoen and Danuj, one could almost be forgiven for thinking that the Union has deliberately taken steps to neuter German nationalism, BUT THIS IS TOTALLY NOT THE CASE.  Relatively industrialized, it's got 9 IC and 5 BP.

Out on the west is the Nordsoen, a collection of recent acquisitions including Denmark and northern Holland, but also some German territories.  11 IC and 4 BP.

Religion in the Union

There is no single, official religion in the Vilnius Union; indeed, the Union's initiating power, the Polish-Lithuanian Commonwealth, was known for its religious freedom and the maintenance of this approach to spirituality was found to be necessary as the Union expanded into different parts of Europe with their own beliefs.

Major Religions:

-Catholicism:  Catholics are the largest segment of practitioners in Rzeczpospolita and Danuj, with smaller communities in Nordsoen and Deutschland.  Catholics - and the Union government - have long grappled with the problem of having the pontiff base in a foreign and sometimes hostile state.  No clear answer has yet been established except that the Church's top official in the Union - the Archbishop of Gniezo (established in 1,000 AD) - tends to be very politically astute and willing to deviate from papal edict where it will conflict with Union national interests.

-Lutheranism:  The dominant religion in Sverige, Lutheranism is also practiced by large communities in Nordsoen, Deutschland, Danuj, Suomi.  There is no single Lutheran church, but rather about twenty, mostly representing former German kingdoms in Deutschland as well as other former nation-states (such as Sweden).  The churches coordinate their activities through the Lutheran Baltic Federation, headquartered in Uppsala, Sverige.

Regionally Significant Religions

-Calvinism:  Initially limited to areas of Deutschland and Danuj, the Union's Calvinist community grew significantly with the annexation of the northern Netherlands.  A gradual merger of Dutch and German churches resulted in the formation of the North Sea Reformist Church, governed by an elected synod.  Its administrative headquarters is in Emden, Nordsoen. 

-Judaism:  A legacy of old Poland's religious tolerance is that around sixteen percent of people in Rzeczpospolita are Jewish, with smaller communities in Deutschland and Nordsoen.  This in all probability means the Union hosts the largest single population of Jews in the world.   The Chief Rabbi of the Vilnius Union typically (and currently) heads the yeshiva in Krakow, Rzeczpospolita.

-Orthodox Catholicism:  There is a long tradition of Orthodoxy in parts of the eastern Rzeczpospolita and Suomi.   Sometimes led from Moscow, sometimes from Kiev, the church was thrown into much disarray during the Mongol invasions.  However, the survival and eventual growth of the Polish-Lithuanian Commonwealth allowed the faith to regain its footing.  The head of the Orthodox Church in the Union is the Patriarch of Minsk.

~Rationalist:  Not religious but rather irreligious, Rationalists are a small but relatively vocal and well-educated minority in the Union's larger urban centres, particularly those in Nordsoen, Deutschland, and Danuj. 

-Anabaptism:  Small, pacifist communities exist in the rural areas of Deutschland, Nordsoen, and the Rzechpospolita.  Their refusal to accept call-ups to Universal Service have been the source of sporadic conflict and annoyance amongst their neighbours and the chattering classes.

General History...

Generally speaking, the history of the Baltic broadly follows historical trends, if not specific events, up until 1647.  Four notable differences apply up to or at this point:

1)  Russia is much smaller and less powerful, being under pressure from the still existant Golden Horde to its east.

2)  Sweden is constrained by the presence of a sometimes hostile Northern Kingdom to its north.

3)  There is a Byzantine Empire in place of the Ottomans, and a different but not hugely different Hapsburg Empire.  There is also an actual Roman Empire, so no Holy Roman Empire; the German states are a little less organized in one way, but also sometimes leery of the larger empires to their south and east.

4)  Crown Prince Sigismund Casimir of PLC survives his historically terminal illness in 1647, meaning that the House of Vasa is the surviving royal house of the Union.

5)  A near future difference is that the "Deluge" of 1655 applies not to PLC, but to Russia, leaving PLC strongish and religiously tolerant.

Timeline:

1650:  The historical-ish Khmelnytsky Uprising begins as Cossacks in not-Ukraine rebel against the PLC.

1654:  Having defeated PLC efforts to suppress them, the Cossacks declare the Hetman Khanate, and become an ongoing nuisance to all of their neighbours for the next two centuries.

1655:  Now quite isolated from the rest of the PLC, the Grand Duchy of Greater Moldova separates from PLC and swears allegiance to the Hapsburg Empire.

Russia attacks the PLC at this time, initiating the Second Northern War

1657:  The Horde and then Sweden intervene in the Second Northern War

1660:  Russia falls; Sweden, PLC gain some territory but Horde occupies most of it.  PLC swamped with refugees fleeing from the east.

1675-9:  Scanian War, Sweden vs Denmark/Netherlands/Brandenburg-Prussia, generally inconclusive.

1700-16:  Great Northern War/War of Swedish Succession.  PLC, Denmark, Saxony, Brandenburg-Prussia and the Horde (independently) attack Sweden ad its Dutch and Holstein allies.  Sweden strikes hard at Denmark, knocking them out of the war.

1701:  Swedish invasion of NE PLC ends near Riga as Charles XII dies in battle against Polish-Saxon army.

1702:  Sweden sues for peace, loses Suomi region (much of it already overrun) to PLC.  Charles XII's elder sister takes Swedish throne.

1703:  Horde attacks Sweden; PLC enters on Swedish side.

1707:  Horde repulsed.

1708:  Queen of Sweden dies of smallpox.  Different factions back her son or her younger sister for the throne.  Power struggle ensues, Germans/Danes intervene on son's side, PLC intervenes on sister's side.

1716:  Peace.  PLC-backed Ulrika married to heir of PLC, personal union formed between PLC and Sweden.

1741:  With the coronation of Sigismund V and Ulrika's eldest son Stanislaw I, PLC and Sweden merge as the Vilnius Union.  War of Baltic Unification sees Denmark, Netherlands, and German states attack Sweden/PLC in an effort to prevent the formation of a new major power.  The new Vilnius Union fights defensively, focusing efforts on conquering and annexing Prussia in order to secure the Union's interior, and ultimately prevails.

1756:  War of German Unification begins as Vilnius Union and Hapsburg Empire cooperate to prevent the unification of various Germans states into another major power.  The Hapsburgs attack into Bohemia, while the Union invades Brandenburg and Saxony.  Denmark and the Netherlands opt for neutrality, not seeing an upside to either a German victory or defeat.

1759:  Brandenburg conquered by the Union.

1761:  Saxony conquered by the Union.  Bohemia conquered by the Hapsburg.

1762:  Joint invasion of Bavaria ends fairly quickly as Bavaria surrenders to the Union (only).  Union and Hapsburger forces clash for several weeks before Hapsburger forces withdraw to Bohemia and their own territory.  End of the war.

1778:  "Das Bankett" begins as the Union begins using diplomatic means to entice minor German kingdoms, duchies, and statelets to accept annexation into the Union.  This is most effective with Lutheran-majority states who find the Union's position on religion more bearable than the Roman or Hapsburger states also vying for major power status on the continent.

1788-90:  Catherine the Great's War.  Northern Kingdom and Vilnius Union go to war over border demarcation in Scandiniavia.  Uprisings in Saxony and Brandenburg cause considerable difficulty for the Union, which sues for peace and cedes a long, narrow strip of land in Scandinavia to the Northern Kingdom.

1797:  Second Brandenburg Uprising.  Connections between the rebels and the Danish government are discovered, leading to a state of war between the Union and Denmark.

1799:  Battle of Kopenhagen sees the Danish navy destroyed in action against the much larger Union navy, followed by troop landings and ferocious fighting that damages much of the Danish capital.  Denmark surrenders and is annexed into the Union.

1813:  Das Bankett ends with the Union invasion of Wurttemburg, Hohenzollern, and Baden.

1815:  An impromptu alliance of surviving, independent German states crumbles in the face of a major Union attack on Osnabruck.

1817:  The last German states are incorporated into the Vilnius Union.

1829-31:  Hetman Cossack raids into Poland trigger three years of cavalry actions, ending with the slaying of the Hetman Khan in action on the border.

1854-8:  Sporadic border conflict with the Horde.

18XX:  The big thing where Rome and the Union smoosh the Hapsburgs and gobble up everything between them.

Monarchy in the Vilnius Union

Note:  This is as of 1910.

Sigismund VIII Vasa is the King and head of state of the Vilnius Union.  Eldest son of Michal II and Queen Ingrid, he is fifty-three years of age and inherited the throne in 1903.  He is married to Queen Sophie, of the Bavarian Wittelsbach.  They have three children:

-Gunther (23) is the Crown Prince, and is recently married to Christine of Brunswick-Wolfenbuttel.  Per tradition, he serves in the Union Army as a cavalry officer.  He saw limited combat in North Erika during the Union's initial conflicts there in 1910, but his unit is currently stationed near Frankfurt.

-Wiktor (21) is currently single and per tradition serves in the Union Army as an infantry officer.  He is currently stationed somewhere in Choco.

-Marie (11) is but an unexpected gift, born three days after her mother's forty-third birthday.

The House of Vasa (founded 1523 with the ascension of Gustav I to the Swedish Throne) is the royal house of the Vilnius Union.  The monarchy's role in government has gradually decreased over the past four centuries and is now largely ceremonial; the primary power resides in the elected Sejm and the Prime Minister there. 

Succession is through male-preference primogeniture. 

The Vasas are Catholic, though a cadet branch in Sverige (well out of the line of succession) is Lutheran.

The family's primary residence is the Palace of the Grand Dukes of Lithuania in Vilnius.  The original palace, dating back to the 15th century, was largely destroyed by fire in 1819.  The current structure was built on the same grounds between 1824 and 1829, during which time the royal family took up full-time residence at Stockholm Palace, normally the family's summer retreat.  In recent decades, a winter compound - simply known as "Rotes Häuschen" - located south of Munich has hosted royals seeking to engage in skiing and bobsledding.