The player's country:
- is in the Muslim religious group.
The player's country:
You'll want both Castile and Aragon to rival each other. This way when they end up fighting each other you can swoop up and grab the European provinces. From there, it's the usual Ottoman start. Annex Byzantium, Athens, and the Anatolian Beyliks. Set your national focus to admin as you will need it. Reclaim any cores that you have except for your core in Qara Qoyunlu because you need to save your manpower. Genoa is almost always willing to give up their islands if you threaten them with war and Venice will often give up their islands to a threat of war if they are embroiled in a war themselves. Build up your armies and navy to be ready for the first war with the Mamluks around 1460.
After expanding eastwards through Anatolia, it is recommended to build a fleet of galleys and carrier ships and conquer the provinces required from Naples and Aragon, as if the player leaves it for late game it will be harder to achieve as they will be under the control of Spain through the Iberian wedding event.
Take the mission to conquer the Levant which will give you claims on all Mamluk land through to Egypt. Declare your first war and take as much land as possible. It is not possible to take all the land in one war but that is no matter. After coring the recently conquered lands, declare war on Cyprus. The Mamluks start with a guarantee of Cyprus so should come to their aid. Finish taking the rest of the Levant from the Mamluks and annex Cyprus.
After conquering the Levant and the northern Hejaz provinces look in the Arabian peninsula for a country which is now small but has lots of cores to vassalise, i.e. an empire that rose and fell. Spend the time that you have a truce with the Mamluks feeding land to your Arabian vassal.
If you have spare time during your truce you can clean up Trebizond, Aq Qoyunlu or maybe some of the Balkan nations. You should also have reclaimed most of the Italian provinces around the Black Sea, Anatolia and Greece.
Land of the Pharaohs
Take the mission to conquer Egypt which will give claims on all of Egypt. Declare war on Mamluks and take their CoT's and Cairo to further inhibit their ability to defend their meager empire. After the first war, continue expanding your Arabian Vassal and begin their annexation. This is a good point at which you should have the manpower to expand into QQ. Take your core and all the northern provinces you can, avoid taking Iraqi provinces as you will get a claim on these later from the Conquer Mesopotamia mission. Declare a second war on the Mamluks and bring Egypt into your control.
At this point you should be in control of Greece, Anatolia, the Levant, Egypt, all Eastern Mediterranean Islands and most of Arabia. If you also control parts or all of the Balkans it is an added bonus. You should now start the push towards Southern Spain. In order to unify Islam you must conquer Southern Spain, Sicily and all of North Africa. You can either threaten or actually declare war on Naples and Aragon for Southern Italy and Sicily. Use your missions that give you claims on Tunisia and Tripolitania to conquer those regions, and then conquer the rest, or vassalize a Berber nation such as Algiers, which you get a mission to subjugate, and feed your vassal the rest of North Africa and then start integrating them. (Increased coring cost in North Africa affects vassal integration cost so vassal feeding does not save monarch points.)
Alternative Ottoman strategy
Ottomans is a large nation sitting on one of the best trade nodes in the game. As a result Dar-al Islam is an achievement easily doable with Ottomans. Some strategy points depend on whether you just want to obtain the achievement or play the most expansionist game.
Start with conquering Candar and Constantinople and Kosovo for the gold mine. Delete or sell your transports and capture as many of their galleys as possible. Don't be afraid of exceeding the naval limit. Do not take many other provinces from Byzantine than Constantinople to keep the aggressive expansion in Europe low. Keep your focus on Military. Owing to one of the best starting monarchs, Ottomans will probably first tap into military tech 4. Difference between tech 3 and tech 4 is huge as your military tactics will be almost twice that of nations at tech 3. Declare war on Mamluks a few months before you reach tech 4 and have your first land battle after you reach tech 4. Capture at least 12 transports. Don't worry, they have plenty and Fezzan will probably add to the numbers. Get 100% worth of provinces including a Syria core and Suakin, the southernmost point of Mamluks. From there, form a claim to Yemen and declare a war instantly on Cyprus for a white peace. All it takes is to end the siege in Cyprus. This way, you effectively reduce the truce length to 6 years, assuming you can obtain the white peace in one year.
If you only go for the achievement, the next step is to declare war on Qara Qoyunlu with reconquest CB of Syria and obtain one Iraq core that you can create Iraq. You should also declare war on Yemen and vassalise it. It has many cores, including Aden. Work your way through Hadramut and Mahra to vassalise Oman. Oman has many cores to reconquest , including Muscat and can be vassalised peacefuly. Alternatively, if Hormuz lost its power, try to vassalize Hormuz and reconquest Muscat.
If you want to focus solely on the achievement, in your next war with Mamluks, just reconquest Damascus and get Mecca from Hedjaz. Even though you defanged Mamluks in the first war, they are still dangerous, so try to declare war just before you reach another Military tech. If you plan to expand rapidly, without thinking about the achievement, using the declare war on Cyprus trick, it is possible to annex the entire Mamluks before 1480. Either get the forts, or alternatively get provinces close to the forts. They leave their forts mothballed so you can capture most of Mamluk forts within the first month of your war.
Medina is just there, so there is no hurry to capture it. You should divert your focus to Qara Qoyunlu for Iraqi cores, one of which is Bagdad. If your focus is the achievement, Dagestan is a long way to go, so just vassalise Shirvan and make it hold Dagestan. Otherwise, make your way through Dagestan either peacefully, i.e., vassalise Georgia and reconquest its many cores, or aggressively. Since the only large country with huge AE will be Mamluks, as long as you declare your upcoming wars to Mamluks just as soon as the truce ends, even if you go for the aggressive way, no coalition will be formed against you as long as you keep Austria, Poland and Timurids happy.
Remembering that we avoided as much AE as possible in Europe, we cash this by transferring entire Naples using the 1st age ability, transfer subject. The needed cores are Naples cores so we can get them in the next war with either Castile or with Aragon. Sitting on both Aleppo and Alexandria nodes, Ottoman trade should be very strong at this point, helping you either to get more skilled advisors for Army Professionalism or to hire many mercenaries. If you are fighting against Castile, you can casually get Cordoba during the Naples reconquest war. If you really want to expand fast, you can try to snatch away Aragon from Castile using transfer subject, after the Sicilian cores are returned. Before the cores are returned, Aragon is too large to snatch, even with the transfer subject.
The hard part of Dar-al Islam is that the required territories are too far away from each other. But now, we need three more provinces to go: Samarkand, Ifni and Thatta. If Timurids explode, you can vassalise Khorasan and Afghanistan to reduce Timurids to a vassalisable size and then vassalise it to reconquest Samarkand. Otherwise, you can simply snatch Transoxiana along with Samarkand with transfer subject. For Thatta, buy a province in the region for a trade company and expand to Sindh. Sindh regularly allies with Hormuz, so you can declare war on Hormuz and capture Thatta from Sindh. You can work your way to Ifni either by making Naples to make a claim in Tunis and hopping to Ifni, or by declaring a no-CB war to Morocco or whoever holds Ifni.
In contrast to previous patches it is not necessary that all provinces follow a Muslim faith. So conversion of provinces is not necessary and the Dhimmi privilege “Guaranteed Dhimmi Autonomy” can be used to reduce the impact of heathen land.
Morocco deserves a special mention as an alternative starting nation. It has the unique ability to take on Spain early in the game, taking advantage of one of their inevitable conflicts in Europe to claim the province. Morocco also has the ability to cut through technologically inferior West African and Ethiopian tribes to Aden, leaving conquest of the Ottomans until the end. Egypt is not required for the achievement, making expansion through West Africa a cheaper option with provinces whose trade can be pulled to the player's home node.
As long as they can survive the death of their first monarch, Timurids have high potential for this achievement. A no-CB war declaration to Byzantium and vassalising them scuttles mission tree dependent Ottoman AI expansion. Byzantium cores can be extracted from Ottomans while Iraqi and Syrian cores are similarly obtained from Qara Qoyunlu and Mamluks respectively. Using Syrian and Byzantine provinces to build a formidable navy, other provinces can be obtained similar to the strategy described by Ottomans.