Well, history said the 4th prince will go for the throne at Jian Wen 4th Year. For better or worse, he is going to be emperor through rebellion and war. He was so angry and despise Emperor Jian Wen and he burned and eliminated all the historical track of him. He basically try to erase Emperor Jian Wen from history by naming his dynasty as Hong Wu 32nd year. Hong Wu is his dad where his dad's reigned until 31st. Hence, the name of the show.
Anyway guys, if you go through briefly all the emperors in the history of China, most emperors are evil. They killed a lot of people and betray many people that put trust on them.
although true, YongLe emperor (Chu Dai or Joe Ma), did indeed rebel within 4 years and tried to erase JianWen emperor from the history books. No historical records show that he despised him. As history said, he was threatened when he and the other prince were separated and most of them stripped of military power. Although in human nature, anyone would be pissed if your father chose a grandson to succeed him and not you (a son)
and just because emperors betray their followers does not make them evil.
Liu Bang of Han eliminated most of his generals/political advisors when he ascended the throne. Emperors thought that people who help fight wars might one day have too much power to overthrow them.
KangXi eliminated Obi (the head of the 4 protectors during his teenage reign) and Wu San Gui (who opened the gates for the Qing)
Tang Tai Zhong of Tang killed his brother and his subjects in order to gain the throne
indeed some emperors becomes tyrants but some who ended up killing trusted people were not evil. Like this series, before Hong Wu died, he told Joel Chan along the lines and I quote "imagine this court is a stick filled with thorns, im eliminating them so in the future you can rule without trouble". Sometimes theyre dont to ensure long term peace in the country.
O and side note: if you search Hong Wu 32, i think it will lead you back to this series and not the actual history. Whether Yong Le changed the reign to Hong Wu 32 is not clear. Unless we find the YongLe encyclopedia (which was destroyed or pieces ended up in different hands)