Very good question (whenever anyone says that to you, know they didn't think you had it in you).

Ancients & Kingdoms Expansion - This introduces 11 new ancient empires from the Elamites and Beaker people to the Xiongnu and Scythian/Sarmatians.

It also introduces a new countersheet of kingdom and common units. Common units are Elephants, nukes and star wars that anyone can purchase provided the requirements are met.

The kingdom units are to fill the void when empires shuffle off the mortal coil.  Of course empires collapsing doesn't mean the people leave, just the oppressive tax gatherers (a reason the western Roman empire collapsed so quickly, the "Barbarians' weren't as greedy, didn't know where the gold was buried and didn't want to torture the children straight away to find out (got to start on the right foot after all)).

This means if you were using that empire as a buffer from your more nefarious neighbours then the kingdom units should still provide that buffer until you can re-orient your diplomatic posture. By the same token the first player after the end of empire doesn't get to fill the void before you or anyone else can react.

The expansion also provides Cadence markers for option 9. This allows the player whose go it is (the first player) to place 3 cadence markers one on each cadence box,

Whoever picks the same action as the cadence action marker on the "-1 Progress box" will not advance this Free Progress step (indeed may go backwards), if on the "-1 if trade <0" then empires with a trade less than 0 will also be -1. On the other hand those empires with trade >1 that do the same action as the Cadence marker on the +1 if progress >+1" will progress an extra space in the Free progress step of the End of Turn.

This adds an entire new level of decision making to the game. "What is the first player likely to do with their empires this turn?" Whatever it is they will not place the cadence markers to slow those actions. I want to do the same actions, if only I can figure out what they might be.

The expansion also introduces a new artefact type, Great Universities with 4 brand new universities and the leaders for the 11 new empires.

Medieval Expansion - This introduces the empire units to allow the 6th player into the game. It also includes 11 new medieval empires from the Ostrogoths and Visigoths (be afraid Goths be very afraid, Alaric is a damnable traitor and can you really afford to give him control of your sole army particularly with that wolfish grin on the player opposite’s face?) to the Mapuche and Iroquois.

This expansion also includes all the leaders and markers for the new player as well as some extra Just rule and Peace Treaty artefacts.

Modern Expansion - This adds the empire units for the 7th 7 Ages player as well as 11 more modern empires from the Brazilian and South Africans to the Soviet Union and New Zealanders. It includes all the leaders for the empires and the markers for the 7th player.

Religions Expansion - This is where we explore the world of religions. There are no empires in this expansion, instead this expansion dramatically adds to 7 Ages religious horizon.

First off we introduce a brand new religion (well not that new I suppose) Judaism. We also introduce a whole bunch of new religious artefacts, like each religion now has a defender of the faith, there are great temples, and each religion (not just Christianity and Islam) can start holy wars.

The centrepiece of the expansion is the temples playable in option 12, Deux Vult! You can build (for free) one temple per civilise (and one more if you have a religious leader) in any area without a temple. Unlike Classic 7 Ages, you don't get glory for being most religious based on how many areas you have, now its how valuable your church is.

Each temple you build consumes half that area's income but gets religious points equal to the income and whoever has the most valuable temples wins. It's a pretty standard gaming device, you don't want to spend too much of your income on your religion just one more than the next highest player with that religion. 

Of course only being one higher makes it very tempting for them to choose civilise and build a temple in a 4 money area which increases them by 2 and they are top instead. And that boys and girls is how religious arms races start particularly as Deus Vult increases the overall glory of religions (everyone can dabble in all religions for glory, it's no longer just the glory interest of a few empires).  

There are also 11 new religious empires included from the Sea People and Kingdom of Israel and Judah to Saudi Arabia and Iran along with the leaders required for these empires (at last it's David v Goliath).

Finally there is a new artefact, Forbidden city and a new event "Golden Age" which gives you all the benefits of an Artist, Builder, Philosopher and Scientist for the entire turn (without eating into your leader max).

Trade & Victory - another expansion off the ranch. Again no new empires, again this is an expansion to explore new realms, in this case trade and victory. First off this comes with the final 11 civilisations, all known for their trading prowess from the Lydians and Aksum to the Hanseatic League and the Gulf States as well as the leaders for these trading empires.

The heart of the system though is secret glory, option 11. If you are tired of "let's gang up on the leader" then this is the option for you. Every time you get glory, you don't record it on the track, you place the glory tokens into your velvet secret glory bag. Sure you can tell how lumpy the bag is but are those 1s or 200s? There are events that pull the veil away but that is spotty and infrequent, particularly towards the end of the game when every glory counts.

If we reach the 2nd stretch goal of our Gamefound campaign, 7 Ages Deluxe pledge backers will receive embossed embroidered velvet secret glory bags where the embroidery alone increases the cost of the Deluxe game by 20% (including the velvet bags it's 30%) for being the pathfinder you clearly are.

Each empire also gets its own homeland marker to place when you start an empire. There is also a "Heimat" event that lets you move your homeland or have one even if you don't have a homeland glory category, all of a sudden yes you do.

To round out the expansion you get several new artefacts including Irrigation, Great Shipyard, Environmental sustainability (and its attendant Climate Clock), Mars Landing and the piece de la resistance General AI.

In the original version, like many games you fall behind you can't win. We've fixed that. Although its not easy, even if you are last, if you get AI first, you win. This makes the end of the game very tense as you not only have to look at who's winning (particularly hard if playing secret victory) who's the most advanced, but also who is closest to completing the prerequisites for General AI and launch themselves onto the winner's podium. This end game twist makes the game tense and victory unsure to the very last card.

*****************************

So as you can see the Expansion adds both width to the game in terms of number of players and depths in terms of ever greater options, actions and decisions. Hope you enjoy it.

PS The reason that this is a very very very good question is because while looking at the prerequisites for General AI I realised that the last prerequisite, Mars Landing is in the Trade & Victory expansion while the sole General AI card was in Ancients & Kingdoms meaning players would need both expansions to play it. 

That is now fixed. General AI has moved to Trade & Victory swapped for Rutters (a new blue artefact) in the Ancients & Kingdoms expansion.