Max Planck began his career in theoretical physics through work on thermodynamics and the second law. After study in Munich and Berlin, he became a professor at Kiel in 1885 and moved to Berlin in 1889. He sought general principles behind physical processes rather than treating theory as a catalogue of separate phenomena. Investigations of heat radiation placed him within research combining precise measurements, mathematics and arguments over the microscopic basis of energy and entropy.

In 1900 Planck developed a formula that described the spectrum of black-body radiation. To derive it, he treated the energy associated with oscillators as occurring in discrete elements proportional to frequency, introducing the constant now bearing his name. The step became fundamental to quantum physics, although its meaning was initially unsettled and Planck did not immediately embrace every later interpretation. It was not a complete theory of atoms or a discovery of all the principles of quantum mechanics. Einstein's light-quantum proposal and later investigations by other physicists extended and transformed the significance of the original radiation work.

Planck also supported Einstein's relativity, taught generations of students and helped shape scientific institutions. The Nobel Prize in Physics for 1918 recognized his discovery of energy quanta. After the First World War he worked to restore German research and scientific cooperation amid national isolation and economic strain. Elected president of the Kaiser Wilhelm Society in 1930, he became a prominent representative of German science. His public authority rested on theoretical achievement and long institutional service.

Under National Socialism he tried to preserve scientific work and appealed against the loss of talented Jewish colleagues, but the institutions he led accommodated discriminatory policies and expelled researchers. Private objections and particular acts of support did not prevent that participation. His presidency ended in 1937. War destroyed his Berlin home, and his son Erwin was executed in 1945 for involvement in resistance to Hitler. In his final years Planck again assisted the reconstruction of research institutions, dying in 1947. The society that adopted his name embodied the effort to rebuild German science after the war. His career joins the conceptual foundation of quantum theory with difficult questions about an influential scholar's response to persecution and authoritarian rule.