In the process of writing, I need to write about a medieval war similar to the first world war or the Peloponnesian War, in which neither side is just or evil, just for the sake of gaining greater international power and land. There is a tit for tat between two powerful neighboring countries. So, I need to write a reason for a war as morally ambiguous as this one. A piece of duchy, the Duke's family died out normally, and the king, as the suzerain, was ready to reclaim the land. At this time, the king next door, who was related to the Duke's family because of a marriage several generations ago, said no, this land should be inherited by me. After all, I am the nearest relative of the heir. So the war began. This is my current assumption. Is this war reason enough to meet the conditions?
Maybe things could escalate slowly, with each side getting more aggressive? Like one side starts flying their flag over the castle, so the other side finds (or pays) some locals to start flying their flag over another village, so the first side starts imprisoning anyone found with the other side's flag, then that side starts saying "We only want people to be free, that guy is oppressing you!" And so on until it's open warfare. Seems like it gives plenty of opportunities for both sides to do morally questionable things until the reader doesn't find one or the other particularly sympathetic.
What is in the duchy? It would be very fitting reason for war if both sides paraded around "inheritance" and "blood relations" but the real reason was the gold/silver mines in the duchy, or perhaps some wealthy townships.
The Duchy is located on the border of the two countries, with a vast area and fertile soil. At the same time, the two countries have long regarded each other as obstacles to development and doomed enemies. This has led to tense diplomatic relations between the two sides.
Oh,!of course! just like what the United States and the Soviet Union did to each other during the cold war.
If there's fertile soil, you'll likely have more population. I can easily see the events play out as: duke dies, both sides make a claim. One side moves in first and starts collecting taxes / administering the duchy. Other side takes this as an act of aggression and sends a raiding party to "remove" the collectors/administrators. War ensues.
That works for me. In fact, didn't that happen between England and France at least twice -- and that's not even discussing England and Scotland.
Quick history refresher: https://www.historyextra.com/period/medieval/where-history-happened-king-john-and-the-french-invasion/
https://en.wikipedia.org/wiki/Pig_War_(1859) didn't really develop into a full-blown war but funny none the less (and true)
From Terry Pratchetts Jingo is a good example where petty arguments over fishing rights between two fisherman progress in to land claims when they discover a "new" island and patroitism forces either sides government to defend their position. Or, From Babylon 5 and the Drasi war for leadership. Purple Drasi vs Green Drasi when coloured bands are put in to a barrel, the drasi pull one out, that determines what side they are on and then they fight until one side wins, they they are the leaders of the race for the next 5 years until it starts again. So there you have two different conflicts, one revolving around pettiness and stubborness, no one wants war but they cant back down, and one around tradition. In neither case is there is no right or wrong side, no evil vs good, or even a real desire for war.
That seems like a very natural incitement of war to me. Entitlement is a good catalyst, and the want satisfies classic, believable motivations (land for taxes, resources, trade, as well as conflict in order to show capability and might). Wars have been waged over things that are ridiculous in comparison.
That was almost exactly what happened to cause the Hundred Years War. Whether you could say neither side was acting from greed for land or power might be open to debate though.
It was once conceived. But in the end, I think power and land are better for the purpose of war, because they are more real and highlight the essence of most medieval wars.
In fact, whatever their excuse, the real purpose of most wars both medieval and modern is land, assets, or power on at least one side. The other side may be motivated by survival or a desire not to be conquered, of course.
Yes, of course. So I now set up the deep-seated reason for the war between the two countries: the two powers hope to successfully destroy each other and make themselves the only world powers. Because they think this is the only way to completely cut off the possibility of their own destruction and conquest.
Please see my final version. The two countries, Empire and kingdom, are the two strongest countries in the world. However, because of the fear of each other's power, the two countries began to deteriorate their diplomacy and military tension. With the development of the situation, there was no possibility of reconciliation between the two sides, so the Empire was the first to stir up military friction on the border, hoping to lead the other side to a complete war. But the Kingdom chose to expand its army to prepare for the destruction of the Empire. Soon after, the Duchy family on the border of the Empire died out, and the kingdom that had completed the preparation officially launched a military attack on the Empire on the ground of the inheritance of the Duchy's land. This eventually led to a long war between the two countries. How about this?