I think the largest of my war containing the most events, and large battles was the Oka war.
The Oka war was the last war Expelling the Shogun forces from mainland Kyushu, they owned a copper mine, 2 coal mines, and 5 provinces. i needed the resources to build up a navy and to expell the dreaded Shogunate off Imperial land, I had started the war with Oka after, building my navy high, and upgrading factories, Inn's, and Farms, my economy was now average, i needed to remove the 3 Oka provinces from Kyushu before pushing for peace, i launched the Ary of west Satsuma, lead by my Daimyo up to Tsukushi, where a Oka army incredibly large met me, i had to retreat.
The Oka force followed me to a river, luckily their was only one way across, so i put my levi in a trapezoid formation around the entrance, my wood cannons would be essential, the enemy launched all their cavalry across, my levi's quickly shot up the cavalry and repelled the first wave, then the real problem, the infantry came, a fierce fight raged for 30 minutes, infantry in melee, firing, only thing going well was all their men were bunched up so every shot hit.
The fight ended, i came out victorious, i charged the retreating army back to their city, where another half stack was there!!!, i thought the western army was done, while my east army was slowly pushing up through Bungo and Buzen, the real fighting was in the west, next turn i retreated into the hills,their armies chased me, but before anything started you wouldnt believe what happened, their 4 star general changed sides, bringing 5 units of fresh levies, i owed alot to this general, if it werent for him i wouldnt of taken the Oka army, the battle was quick and lethal, with new forces and a good general, and the war in the east was noproblem little resistance, and they hated their master, and finally the war of the Kyushu Shogunate forces was over