Simplify the following text for a Grade 7 native English-speaking person.
Original: Tokugawa Ieyasu was the founder and first shogun of the Tokugawa shogunate of Japan , which ruled from the Battle of Sekigahara in 1600 until the Meiji Restoration in 1868 .
Simplified: Tokugawa Ieyasu was the founder and first shogun of the Tokugawa Shogunate of Japan . This shogunate ruled from 1603 until the Meiji Restoration in 1868 .