This guide is a walkthrough to show how to get the Hero's Welcome achievement. Forming Rum by starting as Karaman. This method gets you to forming Rum by 1560 and is great for less experianced players looking for a next level challenge that is still doable.
While any Beyliks in Anatolia (Ramazan, Dulkadir,and Candar) the best nation to form Rûm is Karaman. Forming Rûm through them will give you the achievement, A Hero's Welcome, and they are also the strongest and best positioned of them all. That being said, forming Rûm is by no means a cake walk so there are a few things you want to keep in mind. First off, you will want to Ally with the Mamluks who are already willing to form an Alliance. No matter what the landscape is, you will always need and should always have the Mamluks helping you in the wars to come. Delete the fort in Icel as that is a drain on your already pitiful income, and build up to your force limit. Set your Monarch Focus to Military and have your merchants collect in Aleppo and Constantinople. This is where games will change from here on out. Your rivals will range from Genoa to Lithuania, and at this point it really doesn't matter who you rival. Ramazan and Dulkadir Will either like you or hate you depending on the roll of each game but for the most part you should ignore them except when taking land from them would be incredibly easy, you want to reserve your strength for the Ottomans. Don't ally them as they will never join a war against the Ottomans, the same goes for most other Muslim powers in the region. Your next three allies will come from the other side of the Bosphorous.Hungary, Serbia, Wallachia, and Byzantium are where you should be looking for your next allies, with a emphasis on Hungary. To get them as an ally you may need to build over force limit, get a Statesman Advisor, and/or complete a mission to Improve Relations with another power (Usually a neighboring Beylik). If they get too many relations you will either have to forget about them or re-start which is recommended. Serbia and Wallachia are inter changeable but Serbia is a bit better to have as an ally. Byzantium can be very conditional as you only want to ally them when you are sure they won't be attacked by everyone's favorite Big Green Blob. But they can be a major asset in distracting the Ottomans armies on the other side of the Bosphorous which gives time to you and the Mamluks to take Anatolia.
The last thing to do is to sit and wait for your truce timer (and you allies) to time out. You may also want to wait until the Ottomans get into a war. There is a good chance they will struggle in their war forAlbania but either way their armies will be a good distance away from your territories.
The First and Second Wars
Your first two wars will be the most important, because even after your second war the Ottomans can still kick you and the Mamluks around. Promise you allies land, but only keep your promises to the Mamluks and Hungary. In the first war you will want to leave the heavy fighting to your allies, your job is to siege down most of the unprotected Anatolian provinces and lead the siege at Anarka. Beware as your allies will try to hold the lands west of you for themselves, even the Mamluks will transfer occupation to your other allies (punish them for that latter). When the Ottomans armies do come your way, only engage them when your allies are close and you have the terrain advantage. It's up to you how long you want to stay in the war, and it's all relative to how you think you are doing. However, even if you think your doing bad, you may want to push on as a decisive victory in the first war will set you up well for the second. In the peace deal it is recommended to ignore your cored land and instead get land in the Huvendegar and Ankara areas; if you can try to take all the land in these areas as it will split the Ottomans into several pieces and help you prevent Ottomans access to Anatolia. WIth any war score left you will want to take money, land for either Hungary and Mamluks, and any provinces you may need to form Rûm in that order. You may be questioning why taking these provinces in the first war isn't a priority; it's because you can't form Rûm with out completely defeating Ottomans and Byzantium. So it is better to placate your allies, fill your treasury, and take strategically important provinces first before these. A special note with the Mamluks and land is that you may not actually need to give them land if they have occupied the land that they've marked as interested in. This may still result in an un-willingness to go to war for land for a few years after the truce from this war has gone, so weigh your options ahead of time. It is recommended not to give them land in Anatolia however.
Congratulations! You've successfully declared war on the Ottomans as a minor nation and lived to tell the tale. This totally means that you can declare war on the Ottomans win every time, right? Wrong! The Ottomans are still incredibly powerful, and if they take any land, it will easily offset their losses. Even if you've "wrecked" them enough for rebels to spawn, it's doubtful any lasting damage was actually done. Remain cautious at all times. You will now want to break your alliance with Byzantium as they will just pull you into their own war with the Ottomans with out the Mamluks for allies the war will go very badly for you. The same may go for your other allies (not the Mamluks, join any war they call you in on as they will reliably win their wars) as they may pull you into wars in the Balkans and even pan-european conflicts. Hungary may be the exception, it it worth risking dishonoring a call to war to keep them as an ally, check and double check and calls to war you may get from them. Byzantium, Dulkadir, Candar, andRamazan are all good targets for expansion while you wait for your truce timer to go away and for your next war against the Ottomans. Keep in mind that Aq Qoyunlu holds Ezurum which you need to form Rûm and they often ally with one of the Beyliks at this point. Also watch out and plan for the Ottomans allying with one of the Beyliks as well, usually Dulkadir. It goes with out saying to hold off on these conquests until later.
You best be very careful when declaring the next war, try to pick a time when the Ottomans are at war with a nation or nations that roughly equal their own strength. Beware of the Mamluks military tech level as there is a noticeable delay in institution spread and tech advancement for them compared to Anatolia. Declare at the wrong time and the Ottomans will stack wipe army after army. The second war may also be more you may not have as many allies and the Ottomans at this point will have gathered several to their side. If you've take the Hudvengar area and built a fort in Bigga then you should have little difficulty in gaining control of Anatolia. In the peace deal for the second war, you may now focus on taking the needed provinces to form Rûm, with an emphasis on Constantinople if you didn't take it from Byzantium yourself.
The Wars to Come and the Ottoman Collapse
At this point, the nail has been driven into the Ottomans coffin. Like any cornered dying animal, they are still dangerous, but by now the other regional powers have seen their weakness and will want to carve up what is left. If you witness the Ottomans going into a death spiral, it may be worth it to truce break. The aggressive expansion will hurt you, but hopefully you have taken the needed territory. This means your aim will be to release nations that you can either vassalize or destroy latter. It is recommended to release Epirus, Saruhan, Mentese, Germiyan, and Aydin. Those last two should only be released if some of their cores have already been taken by a stronger power. Finally you should aim to take the entire Thrace area as you will need it to take the Move Capitol Decision to Constantinople (Which adds development,auto converts culture and religion, and upgrades you to Empire status).
The Empire of Rum
Now that you are Rûm (WIth a cooler flag and map color than the Ottomans, thanks developers!), you have become considerably more powerful. But you still have aways to go. Chances are you didn't grab all the Ottomans land, and it may be more difficult to expand into the the Balkans. It's recommended you consolidate your power over Anatolia, taking Rhodes and islands held by Merchant Republics. You may also want to prioritize expanding into the Crimea and Caucasus to head off Russian expansion to those regions. Persia may also provide an interesting area of expansion as historically Rûm is considered a Turko-Persian nation. Arabia is also a good choice for expansion, but be aware that this may turn the Mamluks against you. The lands of the Commonwealth, especially their Black Sea holdings may also prove to be a fruitful area of expansion.