by Udono Nagamochi. Resorting to stealth, Motoyasu forces under Hattori Hanzō attacked under cover of darkness, setting fire to the castle, and capturing two of Udono's sons, whom he used as hostages to exchange for his wife and son. In 1563, Matsudaira Nobuyasu, the first son of Motoyasu, was married to Oda Nobunaga's daughter Tokuhime. Unification of Mikawa In the February 1563, Matsudaira Motoyasu changed his name to Matsudaira Ieyasu. For the next few years Ieyasu was occupied with reforming the Matsudaira clan and pacifying Mikawa. He also strengthened his key vassals by awarding them land and castles. These vassals included Ōkubo Tadayo, Ishikawa Kazumasa, Kōriki Kiyonaga, Sakai Tadatsugu, Honda Shigetsugu, Amano Yasukage and Hattori Hanzō. During this period, the Matsudaira clan also faced a threat from a different source. Mikawa was a major center for the Ikkō-ikki movement, where peasants banded together with militant monks under the Jōdo Shinshū sect, and rejected the traditional feudal social order. Ieyasu undertook several battles to suppress this movement in his territories, including the Battle of Azukizaka (1564). Battle of Batogahara On January 15, 1564, Ieyasu had decided to concentrate his forces to attack and eliminate the Ikkō-ikki from Mikawa. In the Ikkō-ikki ranks were some of Ieyasu's vassals, like Honda Masanobu and Natsume Yoshinobu, who had deserted him for the Ikkō-ikki rebellion out of religious sympathy. Ieyasu was fighting in the front line and was nearly killed when struck by several bullets which did not penetrate his armour. Both sides were using the new gunpowder weapons which the Portuguese had introduced to Japan just 20 years earlier. At the end of battle, the Ikkō-ikki were defeated. By 1565, Ieyasu became master of all of Mikawa Province. Tokugawa clan In 1567, Ieyasu started the family name "Tokugawa", finally making his name to Tokugawa Ieyasu. As he was a member of the Matsudaira clan, he claimed descent from the Seiwa Genji branch of the Minamoto clan. However, there was no proof the Matsudaira clan are descendants of Emperor Seiwa. Yet, his surname was changed with the permission of the Imperial Court, after writing a petition, and he was bestowed the courtesy title Mikawa-no-kami (Lord of Mikawa) and the court rank of . Though the Tokugawa could claim some modicum of freedom, they were very much subject to the requests of Oda Nobunaga. Ieyasu remained an ally of Nobunaga and his Mikawa soldiers were part