In the meantime the Emperor Ko-mei, father of the reigning monarch, had succeeded Ninko on the throne, and the era bore the title of Ka-ei. It lasted until 1854, and it was when it was in its fourth year that Yoshida went to Yedo and there met, as described in a previous chapter, with Sakuma Shozan, whose pupil he became. At this time Sakuma was forty years old, and Yoshida was twenty-two. From their first meeting Yoshida recognised in the elder man a greatness of intellect and grandeur of aim that fascinated him, and led him there and then to appreciate the opportunity afforded him of becoming Sakuma’s disciple. More especially was he convinced of the soundness of Sakuma’s views on the importance of coast defence, and at his suggestion undertook a journey into the provinces of Sagami and Awa, with the express object of searching out the most suitable positions, from a strategical point of view, for the defence of Yedo Bay. It will be perceived, as constituting a matter of no trifling interest, that the defence of the coast was under anxious consideration two years at least prior to the arrival off Uraga of Commodore Perry and his squadron of “black ships,” so that it cannot be said that these measures were proposed as a direct consequence of the American expedition’s advent in Japanese waters. After visiting Awa and Sagami Yoshida went north to the Tsugaru Straits and Hakodate, having the same purpose ever before him, the strengthening of his country’s defences against the intrusion of foreign powers.