Who presented a case for the separation of powers in his work The Spirit of Laws?

The case for the separation of powers was notably presented by Montesquieu in his work "The Spirit of Laws." Montesquieu argued that political power should be divided among different branches of government—executive, legislative, and judicial—to prevent any one branch from becoming too powerful and to protect individual freedoms. His ideas greatly influenced the development of modern democratic systems, particularly in the United States.