蔡叔度，周文王的第五子，同母弟周武王。他的母亲太姒，是夏朝君主夏禹后代，有莘氏部落之女，也是周文王的正妻，被尊称为文母。太姒与周文王共生十子，其中包括了蔡叔度、管叔鲜、周公旦等人。

蔡叔度从小受到了母亲严格的教育，从未做出违背常理的事情。在周文王去世后，由于长兄伯邑考早逝，蔡叔度的次兄武王继任其位。武王灭商建立西周之后，为巩固政权实行分封制，将管地封给三弟管叔鲜建立管国，将蔡地封给五弟蔡叔度建立蔡国，让他居住在上蔡（今河南省上蔡县）。

当武庚被封为商朝遗民时，武庚并未心悦诚服，因此由三监（即蔡叔度、管叔鲜和霍叔处）辅佐监督他。此后，当三监怀疑四哥公旦有篡夺 throne 的野心时，他们开始散布流言，并最终支持武庚发动叛乱。

然而，在一系列斗争中，最终是由公旦以成王名义平定叛乱，并将管鲜诛杀，同时流放了原本要诛杀的人物——那就是曾经支持过他们的刚刚被废除立场的人士：即风起云涌而来之不满者们——这使得他们陷入混乱之中；然后再一次回归到原来的顺序，而这只是一个例证表明了历史如何因个人决策而变得复杂且充满变数。

至于Cai Shu Du himself, after his brother Wu Wang established the Zhou Dynasty and divided the land among his brothers, he was given Cai for his fiefdom. He became known as the Duke of Cai.

In terms of historical evaluation, Sima Qian's "Records of the Grand Historian" states that "the rebellion of Gan and Cai is not worth recording." However, it notes that when King Wu died and King Cheng was young, there were doubts about who should rule. This led to a situation where ten people related by birth to King Cheng served as assistants to help maintain order in the kingdom. As a result, many vassal states came under Zhou control. According to Sima Zhen's "Annotations on Records of the Grand Historian," during this period there were rumors that some individuals were plotting against others; however these plots ultimately failed.

The three sources listed below provide more information on this topic:

Sima Qian: Records of the Grand Historian

Sima Zhen: Annotations on Records of the Grand Historian

Ban Gu: History of Han