After Cao Cao's son Cao Pi started the Wei Dynasty in 220, Liu Bei also wanted to be an emperor and declared himself Emperor of Shu Han in 221. He considered himself the righteous heir of the abdicated Han emperor Xian. Sun Quan declared himself "King of Wu" in 222. Liu Bei found that offensive, and launched a great attack against Sun Quan but failed—due to Lu Xun's great tactics. He died a year later.