Complex sentence: Nevertheless, Toshiie was a very powerful lord, and the close friend and confidant of Toyotomi Hideyoshi, and it was only his death in 1599 that prevented him from playing a larger role in the establishment of the Tokugawa Shogunate.
Split into simpler sentences: Nevertheless, Toshiie was a very powerful lord, and the close friend and confidant of Toyotomi Hideyoshi. It was only his death in 1599 that prevented him from playing a larger role in the establishment of the Tokugawa Shogunate.