So, I am writing a story that will span four centuries. It will start from the middle of the Third Era and might go into the time of Skyrim, depending on certain lore added in the game. I want to know is how does the politics work and how does it match the Roman Empire and such? Taxes, loans, military forces and etc. I need at least a website or something that can explain it to me better. Which crisis did we know happened before the Oblivion and the Dagoth Ur conflicts? Was there any civil forces that caused unrest?

Since my two characters will learn from an early age how politics, the human mind and society in general work, they seek to manipulate some things to bring more influence to themselves and power to secure a high place in the political station. But I must know how it all works before just randomely posting something. You lore-wizards must know a few things? Right?

We don't get much (if any) info on the inner workings of the Empire. http://www.imperial-library.info/content/oblivion-brief-history-empire would probably be your best bet. Also check the http://www.imperial-library.info/content/third-era for events that might work.

Later Cyrodiils traditionally kept a House Guard of Akaviri, and the Emperor's chief adviser, the Potentate, was usually of Akaviri descent. Other Akaviri slaves played a significant part in establishing the administrative structures of the Second Empire, as well as in the training of its military. The restructured Imperial legions, which learned an unparalleled measure of coherence, logistics, and discipline from the Akaviri, began to easily overwhelm the other regional armies

Administration in the Second Empire owed its efficiency to the Tsaesci, and I wonder if the Third didn't just co-opt those ways, or if they were more traditional. Things seem to be very compartmentalized, in the Third Empire (bigger, less efficient). Nibenean society breaks down like this: Thousands of workers ply the rice fields after the floodings, or clear the foliage of the surrounding jungle in the alternate seasons. Above them are the merchant-nobility, the temple priests and cult leaders, and the age-old aristocracy of the battlemages. The Emperor watches over them all from the towers of the Imperial City, as dragons circle overhead. Everyone seems to stay in their place.

Here's what a Templar had to say about times in Cyrodiil: Uriel Septim is sick, and wizards say his heir, Geldall Septim, and the younger Septims, Enman and Ebel, are just doppelgangers placed in the household during Jagar Tharn's tenure as Imperial Battlemage. They say the Guard charged a mob demanding destruction of the false heirs... lots of folks were killed. In Morrowind, our Spymaster was recalled to the Imperial City, to better protect the Emperor. The Emperor and his Council have already forgotten your back-water assignment. Or they just really trust you'll do your duty. Anyway, that's all the interesting stuff I know about Cyrodiil's politics. Mede's a different animal.

Thanks. It was a bit vague, but nevertheless gave some info.

Colovians think Nibenese are effete snobs, Nibenese think Colovians are uncouth barbarians, and Imperial society works because their mutual distrust is weaker than their desire for Cyrodiil to be the ruling province, which requires the rich breadbasket of the Niben to supply the powerful Colovian military force. My sources for this are mostly bits of Oblivion dialog and a few lines from the novels, but I see no reason to disbelieve it.

The Imperial Emperor is the highest in command person.
The throne to the emperor's seat is claimed by the descendant of the last Emperor.
If for some reason there is no Emperor the Elder Council governs in the place of an emperor.
The elder council can make decisions on each own even when there is an emperor,but the emperor can veto a decision if he likes.
Each city state has its own King and Queen that govern them,but both Kings and Queens answer to the Emperor and must oblige to the Emperor's will.
Cyrodill has a capitalist free market,and we could say that the Imperials are mostly liberals.

Well, Alithinos, not quite. The power of the emperor depends on how powerful the emperor is. There were emperors who could run around naked in the Imperial City and thrust in the faces of the council members for all of the public to see, and there were emperors who were just emperor in name only.

Also, why would the Cyrodils be liberals? You got Colovia, which is a part of the country that closely identifies with nords, live simple lives, and strong military traditions. Then you have the Niben, home to many fertile lands, bright and extravagant clothing and fashions, everyone being part of a cult, and home to the greatest smooth talkers and barterers.

Also to point out, it's not really a free market, as there are guild systems in place.

I said liberals because I can't see to name them something else.
They don't seem like communists,socialists or naz(t)i-onalists either.
While there are guilds,their market seem more liberal and free than in other systems like communism and socialism.
Communism doesn't allow you to own anything and socialism puts certain limits for how much things should be sold.
In Cyrodill it seems anyone can own anything,and sell anything at any price. :unsure:

I think the term you are looking for is capitalism, rather than Liberal/Conservative. I am sure that theres a good chance that there are both liberal and conservative merchants in Cyrodill. Naming your own price and bartering was a well practiced tradition back in the day. Hell, even today to some degree outside of modern retailing.

Merchants do seem pretty guild free, I admit, but other trades hold onto guildsmanship, such as The Mages Guild, Thieves Guild, and so on. A guild is basically a legal monopoly. One can't simple just teach magic to anyone willing to pay, one has to be in the Mages Guild to teach and to be allowed to be taught there. The MQ of the Fighters Guild in Oblivion was basically enforcing guild policy. Technically, The Blackwood Company was breaking the law for existing, unless the definition of "guild" was changed.

Though, I guess Thieves Guild isn't legal, but they do go after freelancers and competition. Same with The Dark Brotherhood.

Plus, the merchants guild is boring, and therefor not shoved in the PCs face. It's like the missing hundreds of square miles of forest, or the thousands of Chorrolites who don't have any time for a smelly wanderer. Given the ridiculous extent to which the guild system has spread (thieves guild, anyone?) I assume they're the foundation of the Imperial Mercantile system.