Hello and welcome to my first guide on Steam !

I've read that the achievement The spice must flow was one of the hardest if not the hardest achievement the game has to offer.
Having completed it not a long time ago on my second attempt, I decided to share some tips and how I did it without too much trouble.

I will explain, step by step, how to complete that achievement.
As each game is different, you might have to adapt the guide a little to fit your current playthrough even though it should be roughly the same steps.

Things important to know for your whole playthrough :

• Try not to have too much tyranny (>10), it takes a lot of time to go down especially at the beginning.
  
• Try not to have civil wars, you'll spend a lot of time for something you can avoid. So take care of the loyalty well.
  
• The republic system was the most annoying thing is this playthrough.
  Basically, if you have a score below 30, you can't do anything diplomatic-wise.
  If you have a score below 50, you gain tyranny for a bunch of action you can do.
  So the best is to be above 50, which won't be easy depending on several factors, including RNG events.
  The best thing that helped me about it was to enable the law to make the ruler leading during its whole lifetime.
  
• I played almost all the time on really slow and controlled every army manually.

You start as Mosylon, a weak country surrounded by weak countries.

We will prepare the future by investing the technology points in the religious tree, the goal is to have these :



They will speed up the religious conversion which then will speed up the cultural assimilation.

Your goal here will be to capture your two neighbors to own all the locations within the red border on the screenshot below.
Your neighbors, unfortunately for you, have a defencive pact, you won't be able to conquer them if you attack them alone.

Start by making some claims with the mission tree so you won't spend your influence.
Hire the least expensive stack of mercenaries to help you conquer your neighbors (don't wait for the claims to be done, hire them directly).
They will take some time to come in your country and they'll have to replenish their morale.

Tip : during the start, don't bother with buildings, they are useless. Destroy them if you want some cash for mercenaries.

Once the claims are done & the mercenaries are ready to fight (if they don't have 100% of their morale, it doesn't matter, even something like 50% is enough combined with your levies), it's time to declare war.
With your levies and the mercenaries you should be able to take down easily your neighbors and conquer them.

You should have by now the red area :

Do not lose time, and conquer all the other small nations next to you.

The only big threat here is Kush, but it won't be able to reach you for now, we will take it down in the step 3.

With the claims you did in the step 1, you should be able to declare war to some nations next to you. If you think a war is impossible or too risky to win (possible if two or more nations have an alliance), feel free to make a temporary alliance with someone (that is what I did) and then declare war.

Tip : always try to have cash for mercenary. Do not spent cash for useless thing like buildings. Even if you think you have too much cash : good, you'll be able to buy the mercenaries hired by your enemies with a bit of luck! We'll make buildings later.

Do not forget that for conquering a piece of land during a war, you country must be directly connected to that piece of land, so try to colonize the inhabited locations as soon as possible if required, otherwise you won't be able to capture them.

After a few wars, you should own roughly this area :


If kush has expanded too fast south or did some allies, it'll harder but not impossible.

Time to take down our first big fish, but not the biggest unfortunately for us.

You won't be able to conquer Kush in a one-shot, but with at least two wars.

The steps are the same as previously : hire mercenaries, try to keep a bit of cash to buy back mercenaries from your enemies, and manage your forces well.

Tips : by buying mercenaries hired by your enemy, you can go above the maximum mercenary stacks you can buy by yourself. For example, if you can buy only 1 mercenary stack and your enemy has hired one stack, you can buy it back (with a bit of luck) and have 2 stacks.

At this point it is too dangerous to assault forts, so wait.

If Kush has too much levies, try to gather all your forces at the same place, and attack their armies one by one as they won't probably gather all their armies at the same place. That is how I won my first war against them, they had more levies than me even with my mercenaries, but they did the mistake to split their forces, resulting in their partial destruction, a retreat and a victory for me.

Once the first war with Kush is over, you can start expanding north at the other side. Basically, you have to conquer everything except Egypt. It should be easier than with Kush.
Here again you'll probably need at least two wars to conquer everything.

Here is what I did :

First war with Kush => Expand north to the other side => Second war with Kush => Expand north to the other side => Conquer what's left expect Egypt.

Meanwhile, try to convert your arabic pops by modifying the policy if needed. You can put a young governor so it won't die fast and its policy will last longer (so you won't spend too much influence).

After all these wars, you should have :


I don't remember the exact time I did have that, but it was around 500-520.

The only real challenge of this achievement : conquering Egypt.

Before I explain the strategy, let's plan the future.

It's important to prioritize two research :
a) Conquering by spears, which will help to conquer the big ones : Carthage, the Seleucids, and Maurya. It'll help reducing AE (aggressive expansion) to make war faster.
b) Anything that help with cultural and religious assimilation, and happiness of unintegrated cultures.

One thing I haven't speak about yet : at this point,I didn't assimilate other cultures so I hadn't a lot of levies. We'll speak about it later.

With that in mind, let's talk about Egypt. They're very strong. Too much for us. If you attack them in a war one versus one, you will be destroyed.
That's how I failed my first attempt, I got too much confident and got absolutely rekt.

You will have to do a blitzkrieg.
So start by making some claims, I made claims on their richest provinces which are of course :



Wait for them to be at war with someone strong, like Macedon or the Seleucids.
Put all your forces at their border, including your levies and your mercenaries.
Declare war and rush them. Capture your wargoal first so you might get a peace treaty faster.
If you have enough money and they send mercenaries at you, you can try to buy them. It may fail though, keep that in mind. You can only do that one per year.

They don't have a lot of forts in the center, so you can rush them there too to gain points.

If everything went well, you should be able to capture their richest provinces and some other bits, and the hardest part for this achievement has been done, congratulations !

The first thing I did was to assimilate their culture, so my levy amount went to the sky.

Now the next thing is to expand west and let the east for later.

Do some claims on Carthage. By that time, Conquering by spears research wasn't ready for me.
I suggest you to do a second war with Egypt though do gain more pops before going full west.

I don't remember at what time I did get there, but it was probably. around 530-550.

Here is what I got :


You want to know why I didn't bother to finish off Egypt ? Simply to avoid getting another war, which means getting more AE thus wasting time for a war with Cartage.

At this point, it should be easy.

I did a first war with Carthage to gain control of two of their provinces :



Then after waiting a bit, I finally got the Conquering by spears research, which mean I could take Carthage down with one big war.

But don't be confident : Carthage is a strong rival. You'll have to put all your levies and the best mercenaries you can have at their border (that's why having captured some provinces close to their mainland was a good idea) to once again do a blitzgried.

I suggest you to control all your armies by hand in a Conquering by spears war. It can be tedious to do, but you have to destroy or at least make all the enemy to retreat. Why ?
With conquering by spears, when you take control of a location, it becomes yours instantly, resulting in an increased AE which can go very high very fast.
So if your enemy goes behind your line and take control of some of your locations, you'll have to take them back thus having even more AE.

And take care that they don't put troops on their ship and infiltrate your country, you'll lose time and AE.

I managed to capture almost all Carthage with one war, including the required locations with spice in the iberic peninsula without too much trouble.

Once the west is secured, the achievement seems closer : only the east awaits us.

I assimilate the punic culture, which increased once again my levy size.

You'll probably have a lot of AE by that time, maybe some revolts, so take time to build temples or theaters (you should have a good income by now) or even a wonder. With the research you unlocked speeding up the religious and cultural assimilation/conversation, the process should be fast enough to not be bothered by revolts after a few decades.

What I got, including the bits in the iberic peninsula :

Time to conquer the east : the Seleucids and Indus.

Well, I think that at this point you know what you're doing.
You'll have to make a few conquering by spears war against the Seleucids and Indus.
I did manage to have the achievement at 663 (could have lowered it by 10-20 years with optimization) so you have plenty of time if you went fast at the beginning of this guide.

You will have plenty of revolts but that's easy to manage.

My game just after the achievement :

Well, that was a very fun game, but definitely not the hardest achievement!
I think the Pax Aeterna as Rome was harder (but not that hard) and more stressful.

I might have forgotten some bits of information here and here, leave a comment if you want to know more about something, I'd gladly answer.

Thank for reading me and I hope that this guide has helped you !