Body
Patricians and Plebeian joined together in order to overthrow the king, and after that new laws were created. Unfortunately, these laws was good only for Patricians, so most power fell in the hands of patricians.
Also there were economical reasons. During war Patricians could hide behinde the walls, so they were very well protected. On the other hand plebians often had to leave their farmers in order to take a part in the war. At the and of war
plebians didn't have enough money so they had to borrow money from patricians and led to them becoming debtors. At this time if you can't pay you loans you could became a slave and that was very often the case for plebians.
Conclusion
So these political and economical problems have led to revolt. The moral of this story is you have to treat all the people in the same way, otherwise it could lead to some unpredictable consequences.
Rymer, Eric. (2014). Plebeians in Ancient Rome. History Source, LLC. Retrieved 08 May, 2018, from:http://historylink101.com/2/Rome/roman-plebeians.html