Glossary: Leaders:

Gaius: Emperor of Ussura
Knias: Ruler of a Ussuran province
Doumas: Ussuran ruling council of the five Knias plus the Gaius
Vadin: Leader of a Fhideli (Gypsy) caravan

Provinces:

Gallenia: Easternmost province, Era's home, and site of all of Ussura I. Knias: Tamara v'Rissanova
Somojez: Southwestern province, Pyotr's home. Knias: Borin v'Pscov
Veche: Central province, place you met the Fhideli, and saw Mt. Ostrog. Knias: Staver v'Vladimirovich
Rurik: Western province, home to capitol (Pavtlow). Knias: Aleksi v'Novgorov
Molhyna: Northern province, current home of Fleur and Marceau, as well as the nascent Kosar nation/tribe. Knias: Vladimir v'Pietrov; representative on the Doumas: Koshchei the Undying

People you've met:

Tamara v'Rissanova: Knias of Gallenia, member of Sophia's Daughters, rescuee of a certain group of adventurers. Always around light due to prophecy; everyone compelled to tell the truth in her presence. Somewhat quiet and reserved, but with a steely resolve. Inherited spirit skin: The Firebird
Montegue: General of Montaigne army, though Charles met him commanding an eclectic mix of Ussurans in the distant past against gun-weilding bugs. Forthright, keenly intelligent, devoutly religious. Gave Charles a pendant 'for the next time we meet' that turned out to be a church relic.
Piorgi, Renate, and son Rue: Piorgi is the vadin of the Vitzi Basulde (The 'Basulde' clan of the Fhideli), and Renate is his wife, and Rue his son. Rue was quite taken with Pyotr, and warned him when the soldiers were after him.
Fleur and Marceau: Fleur is Raelynn's double, and caused no end of confusion and consternation in Season 1. Has now run off with Marceau (formerly of Devoe's entourage) to the Kosars. Fleur stole a knife that lets her rip open Porte holes and walk through them, despite being only half-blooded.
Devoe: One-time first lieutenant to LaVache, the man who killed Charles' father at sea. Now assigned to a diplomatic post in Gallenia, where he helped stir up an uprising against Tamara by freeing Tamara's erstwhile brother, Dreng. Last seen wandering off in the wrong direction on the wrong side of a Porte portal, then later in Montegue's camp, where he turned out to be a leaping bug.
Palech: A Sud'ya monk you met in Dreng's prison monastery, and also in the past in the Bug War, and also in Kuniew near Mt. Ostrog (modern-day site of the Bug War).

People you've heard of:

Ilya Nikolovich: Gaius of Ussura. Sometimes known as 'Ilya the Terrible', his father was assassinated by the then-rulers of Rurik and Molhyna when he was 9, and Ilya was tortured as they tried to break him and make him into a puppet-king. Rescued by Tamara when he was 15, he killed his oppressors and has ruled with an iron fist ever since.
Ketheryna Dimitritova: Wife of the Gaius (Ilya Nikolovich), native of Eisen. Engaged when her husband was seven, she was told the royal family had died of a sickness that Ilya still suffered from (and thus could not be seen) two years later. Abandoned at court, she spent the time learning Ussuran history and politics, and trying to find out what had happened to her fiancee. When she finally did, she got word to Tamara, who was able to rescue him. Though not a member of the Douma, she often sits nearby listening, and does her part to facilitate things. Was granted Pyeryem (an astonishing thing for someone not a Ussuran native), though the Sophia's Daughters have helped her hide that fact so far.
Borin v'Pscov: Knias of Somojez, but the real Borin was killed accidentally by Pyotr many years ago. The current 'Borin' is actually Valerii, a merchant who happened to look like Borin, and was forced to take his place by members of the Tyomny (the Somojez guard), including...
Usor v'Kaplov: Commander of the Tyomny, one of the group that put Valerii on the throne, and has been pursuing Pyotr to 'clean up loose ends'. (Well, OK, you've met him, but his story makes more sense listed after Borin's.)
Koshchei the Undying: Former ruler of Molhyna, he abdicated rule of the province to his heir while retaining his seat on the Douma, and then... never died. Has been living for over 1,000 years, surviving various assassination attempts. Reportedly knows forms of sorcery that nobody else does; may know something about Porte.
Staver v'Vladimirovich Knias of Veche; went crazy after a visit to the Crescent Empire years ago. Now mostly lives beneath his castle, works on turning it into a great Maze of some sort, and creating clockwork automatons that sometimes get loose and wander the countryside before being put down by groups of hardy adventurers.
Aleksi v'Novgorov Knias of Rurik; his father killed Ilya's father, so the two of them don't really get along much. Leader of the war effort against Montegue; holds the Wolf spirit skin.
(Also note that if you're after pictures, the picture on the cover of the Ussuran book (which also appears in the Player's Handbook) are, from left to right, Koshchei, Ilya, and Ketheryna.)

Other notables:

The Four Beasts The wolf, cat, bear, and eagle that (according to legend) stood outside Matushka's cave while she slumbered, until the First Prophet came to wake her. Nowadays, the wolf spirit skin is held by the Novgorov Knias (Aleksi), the cat skin by the Vladimirovich Knias (Staver), the bear skin by Koshchei the Undying, and the eagle (now Firebird) skin by the Risanova Knias (Tamara). The fifth Knias has a Drachen skin of a Drachen that sleeps underneath Andresgorod Castle, and is held--or, rather, *was* held--by the v'Pscov Knias.

And finally, you all!

Charles Algun (Jota), a sailor whose father (Carlos) was killed at sea by the Montaignian captain LaVache. Later met Louis, who had been a captive on Carlos's ship and the true target of LaVache. Went after Devoe, first mate on LaVache's ship, when he learned he was in Ussura, and has been in Ussura ever since. Current goal: to infiltrate the Montaigne navy (or, barring that, the army) to discover more about LaVache.
Pyotr Ivanovich (katre), a Ussuran axeman who once accidentally killed a boyar...only it wasn't a boyar, it was the Knias of Somojez, Borin v'Pscov (above). Current goal: Get pardoned. This might be a bit more tricky than it seemed before, but finding a worthy Knias for the Somojez throne would certainly be a good start.
Era Khar'kov (Sara), a Ussuran noblewoman with many, many brothers. Left the country for a time partly to be out on her own for a while. Now returned, and fiercely patriotic. Current goal: Do things in Ussura's best interests. If this involves fighting, so much the better.
Raelynn Teresa DuVille (Duchess), a Montaignian ingenue mistaken for a different nobleman's rebellious daughter, and forced to flee the country. Current goal: Find a way to go home. This will probably take a while, so she might as well enjoy Ussura while she's here. She might also be able to learn a new kind of Porte, if she can find the right teacher.
Sebastien (inky), a Castillian-born Montaigne diplomat posted to Ussura, but his superior there (Devoe, above) had already skedaddled. In the course of catching up with him, decided Devoe's activities were a bit beyond the pale, and helped stop him from an assassination attempt. Current goal: Stop the war between Ussura and Montaigne.
Alixandre (nee Alexeij) (Sargent), a Ussuran-born Montaigne diplomat, etc. etc. see 'Sebastien', his friend and cohort, above. Also turned out to be a half-blooded Pyeryem sorcerer. Current goal: Stop the war between Ussura and Montaigne. This is perhaps a bit more personal for Alix, being a native Ussuran.
Vasili (schep), a Ussuran street rat and friend of Pyotr's, also wanted by the Tyomny for being there the night of Borin's death. The favorite of ice maidens everywhere! Current goal: Keep out of jail, have fun, try not to get married.