Simplify the following text for a Grade 7 native English-speaking person.
Original: Ieyasu seized power in 1600 , received appointment as shogun in 1603 , abdicated from office in 1605 , but remained in power until his death in 1616 .
Simplified: Ieyasu seize power in 1600 and received appointment as shogun in 1603 . In 1605 he abdicated from office , but he had the power until his death in 1616 .