- "Every advance reveals a weakness. Wait, and strike."
- ―Sakai Tadatsugu[src]
Sakai Tadatsugu (1527 – 17 December 1596) was one of Tokugawa Ieyasu's most favored and successful military commanders, and one of the "Four Guardians" of the Tokugawa alongside Honda Tadakatsu, Ii Naomasa and Sakakibara Yasumasa. He was the eldest of the four, having served Ieyasu's father.
Tadatsugu was a brilliant tactician with a penchant for fooling his enemies with ruses. In the Battle of Mikatagahara, which saw Ieyasu's army devastated by Takeda Shingen, some trickery from Tadatsugu kept the enemy from pursuing Ieyasu's men as they retreated.