(I made this thread talking about this years ago, but it went nowhere and died. This is more of a remake.)
For context, the Imjin War was an attempt by Toyotomi Hideyoshi to invade Ming China via Joseon Korea. After landing on Korean soil, the Japanese had initial success, even capturing the Joseon capital and forcing the Korean king, King Seonjo to flee North. However, the Japanese effort began to falter, with Guerilla fighters hampering them on land, but mostly because of the efforts of the legendary Admiral Yi Sun-sin, and then eventually Ming Chinese intervention. There was a brief pause for negations but that broke down and Hideyoshi invaded Korea again, but it didn't go well. In the end, the Japanese pulled out after the death of Toyotomi Hideyoshi in 1598. The conflict would effect all three nations involved, as for specifically Japan, it spell the end of the Toyotomi Clan and the establishment of the Tokugawa Shogunate.
There are many theories that historians speculate to why Hideyoshi invaded Korea. Some say it was Megalomania for Hideyoshi to become Emperor of China, or just take Korea, others say it was to weaken Clans after Toyotomi's unification of Japan, others say he just wanted trade concessions, etc. However, one particular theory for this scenario, is that Hideyoshi gotten the idea to invade China from his predecessor, Oda Nobunaga.
Now, I'm going to be honest: Whether Nobunaga actually wanted to invade China is dubious. On one hand, Nobunaga was a prolific conqueror, a great innovator of his time, bold, open-minded personality and his ambitions would've changed Japan greatly. On the other hand, this is the same guy who once called himself the Demon King of the 6th Heaven… as a joke in a letter he wrote to Takeda Shingen who called himself The head priest of the Tendai sect Monk Shingen. So, while speculative, the idea of invading China could've been a joke by Nobunaga. More likely, it was Hideyoshi using it as an excuse to invade and establish a Toyotomi Dynasty over Asia...
However, HYPOTHETICALLY for the purposes of this scenario, the idea of invading the rest of Asia was actually an idea Oda Nobunaga intended eventually to do?
But first, for a POD, Akechi Mitsuhide never assassinates Oda Nobunaga in 1582, and Mori Clan surrenders in order to keep some provinces. Later, the Oda subdues the Chosokabe on Shikoku, the Shimazu, Ryuzoji and Otomo on Kyushu, the Later Hojo in Kanto, the remnants of the Uesugi in Echigo, any remaining Ikko Ikki or other Buddhist warrior monks, and the Date and the rest of the Northern Clans (The last one I think is a lot easier, given that Date Teramune had great relations with Nobunaga.) He achieves Japanese Unification by 1585. This gives him a few years to consolidate the Oda Clan's rule over Japan. He doesn't have to worry about an heir, as Oda Nobutada was an adult and capable military commander. He then also starts preparing to invade Korea, which commences around the same time of 1592 with the Japanese making ladings on Korean soil.
By 1592, ITTL equivalent of the Imjin War is about to begin. How could things go differently?
Without key figures like Kato Kiyomasa or Konishi Yukinaga (IMO, who's rivalry kind of drove the course of the war), who could lead the invasion of Korea (People like Shibata Katsuie, Maeda Toshiie, Akechi Mitsuhide and Hashiba Hideyoshi would've been old, so maybe younger samurai like Mori Nagayoshi or Sakuma Morimasa could be possibilities for command). With different commanders, could the invasion be slower?
Another thing to consider, is there a possibility for Oda Nobunaga to enlist the help of a European power like Spain? Spain did have plans to invade China, and considered allying with Japan to do so, but that broke down as relations began to sour and as Christians started getting persecuted in Japan. With Oda Nobunaga tolerating Christians (At least for now), could there be a chance of an alliance?
However, there is one obstacle that Oda Nobunaga would need to overcome (Besides the will of the Korean people) and that's Admiral Yi Sun Sin. How would the Oda Nobunaga handle the Admiral? If things start going badly as the Korean navy wreaks Japanese supply lines and the wind of Ming Chinese intervention, could Oda Nobunaga reign back his ambitious goals, and keep some small lands on the coast?
For context, the Imjin War was an attempt by Toyotomi Hideyoshi to invade Ming China via Joseon Korea. After landing on Korean soil, the Japanese had initial success, even capturing the Joseon capital and forcing the Korean king, King Seonjo to flee North. However, the Japanese effort began to falter, with Guerilla fighters hampering them on land, but mostly because of the efforts of the legendary Admiral Yi Sun-sin, and then eventually Ming Chinese intervention. There was a brief pause for negations but that broke down and Hideyoshi invaded Korea again, but it didn't go well. In the end, the Japanese pulled out after the death of Toyotomi Hideyoshi in 1598. The conflict would effect all three nations involved, as for specifically Japan, it spell the end of the Toyotomi Clan and the establishment of the Tokugawa Shogunate.
There are many theories that historians speculate to why Hideyoshi invaded Korea. Some say it was Megalomania for Hideyoshi to become Emperor of China, or just take Korea, others say it was to weaken Clans after Toyotomi's unification of Japan, others say he just wanted trade concessions, etc. However, one particular theory for this scenario, is that Hideyoshi gotten the idea to invade China from his predecessor, Oda Nobunaga.
Now, I'm going to be honest: Whether Nobunaga actually wanted to invade China is dubious. On one hand, Nobunaga was a prolific conqueror, a great innovator of his time, bold, open-minded personality and his ambitions would've changed Japan greatly. On the other hand, this is the same guy who once called himself the Demon King of the 6th Heaven… as a joke in a letter he wrote to Takeda Shingen who called himself The head priest of the Tendai sect Monk Shingen. So, while speculative, the idea of invading China could've been a joke by Nobunaga. More likely, it was Hideyoshi using it as an excuse to invade and establish a Toyotomi Dynasty over Asia...
However, HYPOTHETICALLY for the purposes of this scenario, the idea of invading the rest of Asia was actually an idea Oda Nobunaga intended eventually to do?
But first, for a POD, Akechi Mitsuhide never assassinates Oda Nobunaga in 1582, and Mori Clan surrenders in order to keep some provinces. Later, the Oda subdues the Chosokabe on Shikoku, the Shimazu, Ryuzoji and Otomo on Kyushu, the Later Hojo in Kanto, the remnants of the Uesugi in Echigo, any remaining Ikko Ikki or other Buddhist warrior monks, and the Date and the rest of the Northern Clans (The last one I think is a lot easier, given that Date Teramune had great relations with Nobunaga.) He achieves Japanese Unification by 1585. This gives him a few years to consolidate the Oda Clan's rule over Japan. He doesn't have to worry about an heir, as Oda Nobutada was an adult and capable military commander. He then also starts preparing to invade Korea, which commences around the same time of 1592 with the Japanese making ladings on Korean soil.
By 1592, ITTL equivalent of the Imjin War is about to begin. How could things go differently?
Without key figures like Kato Kiyomasa or Konishi Yukinaga (IMO, who's rivalry kind of drove the course of the war), who could lead the invasion of Korea (People like Shibata Katsuie, Maeda Toshiie, Akechi Mitsuhide and Hashiba Hideyoshi would've been old, so maybe younger samurai like Mori Nagayoshi or Sakuma Morimasa could be possibilities for command). With different commanders, could the invasion be slower?
Another thing to consider, is there a possibility for Oda Nobunaga to enlist the help of a European power like Spain? Spain did have plans to invade China, and considered allying with Japan to do so, but that broke down as relations began to sour and as Christians started getting persecuted in Japan. With Oda Nobunaga tolerating Christians (At least for now), could there be a chance of an alliance?
However, there is one obstacle that Oda Nobunaga would need to overcome (Besides the will of the Korean people) and that's Admiral Yi Sun Sin. How would the Oda Nobunaga handle the Admiral? If things start going badly as the Korean navy wreaks Japanese supply lines and the wind of Ming Chinese intervention, could Oda Nobunaga reign back his ambitious goals, and keep some small lands on the coast?
