Qin Shi Huang, the founder of the Qin dynasty (221–206 BCE), feared death and spent the last part of his life seeking the elixir of life. This led to later allegations that he died from elixir poisoning. The first emperor also sent Xu Fu to sail an expeditionary fleet into the Pacific seeking the legendary Mount Penglai where the busi zhi shu 不死之樹 "tree of deathlessness" grew, but they never returned.