The Mongol invasion should have taught to the Japanese the great advantages of co-operating military units, but individual prowess continued to be the guiding factor of field tactics in Japan down to the second half of the sixteenth century, when the introduction of firearms inspired new methods. Japanese historians have not much to say upon this subject. Indeed Rai Sanyo, in the Nihon-gwaishi, may almost be said to be the sole authority. He writes as follows: "The generalship of Takeda Shingen and Uesugi Kenshin was something quite new in the country at their time. Prior to their day the art of manoeuvring troops had been little studied. Armies met, but each individual that composed them relied on his personal prowess and strength for victory. These two barons, however, made a special study of strategy and military tactics, with the result that they became authorities on the various methods of handling troops. In reference to the employment of cavalry, the Genji warriors and the first of the Ashikaga shoguns made use of horses largely, but in later days the Ashikaga did not move away from Kyoto and had no use for horses. Nobunaga, being near Kyoto, and most of the wars in which he engaged involving no very long marches, relied almost solely on infantry. Both Takeda and Uesugi were well supplied with mounted troops, but owing to the hilly nature of their territories, they made no special study of cavalry exercises and, almost invariably, the soldiers employed their horses solely for rapid movement from one place to another; when a battle commenced they alighted and fought on foot. It is therefore correct to say that at this time cavalry had gone out of use. Bows and arrows were, of course, superseded when firearms came into use.
"Thenceforth, the gun and the long spear were the chief weapons relied on. Peasants did not rank as soldiers, but their services were variously utilized in time of war. They were trained in the use of muskets, and of bows and arrows on hunting expeditions, and thus, when hostilities broke out, they were able to render considerable assistance in the defense of their houses. Highwaymen were frequently employed as spies and scouts. Both Takeda and Uesugi sanctioned this practice. These two generals also agreed in approving the following tactical arrangement: the van-guard, consisting of musketeers, artillerymen, and archers, was followed by companies of infantry armed with long spears. Then came the cavalry, and after them the main body, attached to which were drummers and conch-blowers. The whole army was divided into right and left wings, and a body of men was kept in reserve. At the opening of the battle, the horsemen dismounted and advanced on foot. This order was occasionally modified to suit altered circumstances, but as a rule, it was strictly followed."*
*Quoted by W. Dening in A New Life of Hideyoshi.
The artillery mentioned in the above quotation must be taken in a strictly limited sense. Indeed, it would be more correct to speak of heavy muskets, for cannon, properly so called, may scarcely be said to have formed any part of the equipment of a Japanese army until modern times. When the Portuguese discovered Japan, in 1542, they introduced the musket to the Japanese, and the weapon was long known as Tanegashima, that being the name of the island where the Portuguese ship first touched. Thenceforth, the manufacture of firearms was carried on with more or less success at various places, especially Sakai in Izumi and Negoro in Kii. "Small guns" (kozutsu) and "large guns" (ozutsu) are mentioned in the annals of the time, but by ozutsuwe must understand muskets of large calibre rather than cannon.
INVASION OF CHUGOKU.
At this time nearly the whole of central Japan (Chugoku) was under the sway of Mori Terumoto, who succeeded his grandfather, Motonari, head of the great Mori family and ancestor of the present Prince Mori. One of these central provinces, namely, Harima, had just been the scene of a revolt which Hideyoshi crushed by his wonted combination of cajolery and conquest. The ease with which this feat was accomplished and the expediency of maintaining the sequence of successes induced Hideyoshi to propose that the subjugation of the whole of central Japan should be entrusted to him and that he should be allowed to adopt Nobunaga's second son, Hidekatsu, to whom the rule of Chugoku should be entrusted, Hideyoshi keeping for himself only the outlying portions. Nobunaga readily agreed, and, in 1577, Hideyoshi set out on this important expedition, with a force of some ten thousand men, all fully equipped and highly trained. It is noteworthy that, before leaving Azuchi, Hideyoshi declared to Nobunaga his intention of conquering Kyushu after the reduction of Chugoku, and thereafter he announced his purpose of crossing to Korea and making that country the basis of a campaign against China. "When that is effected," Hideyoshi is quoted as saying, "the three countries, China, Korea, and Japan, will be one. I shall do it all as easily as a man rolls up a piece of matting and carries it under his arm."
It is evident from these words that the project of invading Korea and China was entertained by Hideyoshi nearly twenty years before—as will presently be seen—he attempted to carry it into practice. Hideyoshi marched in the first place to Harima, where his operations were so vigorous and so successful that Ukita Naoiye, who held the neighbouring provinces of Bizen and Mimasaka under the suzerainty of Mori Terumoto, espoused Nobunaga's cause without fighting. It is unnecessary to follow the details of the campaign that ensued. It lasted for five years, and ended in the subjection of as many provinces, namely, Harima, Tamba, Tango, Tajima, and Inaba. Hideyoshi then returned to Azuchi and presented to Nobunaga an immense quantity of spolia opima which are said to have exceeded five thousand in number and to have covered all the ground around the castle.
DESTRUCTION OF THE TAKEDA
Shortly before Hideyoshi's triumphant return from his first brilliant campaign in the central provinces, a memorable event occurred in Kai. Nobunaga's eldest son, Nobutada, uniting his forces with those of Ieyasu, completely destroyed the army of Takeda Katsuyori at Temmoku-zan, in the province of Kai. So thorough was the victory that Katsuyori and his son both committed suicide. Nobunaga then gave the province of Suruga to Ieyasu, and divided Shinano and Kotsuke into manors, which were distributed among the Owari generals as rewards. Takigawa Kazumasu was nominated kwanryo of the Kwanto, chiefly in order to watch and restrain the movements of the Hojo family, now the only formidable enemy of Nobunaga in the east.