Haber, Fritz (1868-1934) was a German physical chemist most renowned for synthesizing ammonia from its essential elements, nitrogen and hydrogen, for which he won the 1918 Nobel Prize in chemistry. From this work, he also derived an economical process for mass production of nitrogen fertilizers, which greatly benefited worldwide agriculture.

Haber studied at the University of Berlin, the University of Heidelberg, and at the Charlottenburg Technische Hochschule, where he earned his Ph.D. degree in 1891. He also did post-doctoral research at Zurich's Eidgenssische Technische Hochschule as well as the University of Jena. He worked in his father's dye importing business for six months during this time.

In 1894, he became an assistant of technical chemist Hans Bunte at the Karlsruhe Technische Hochschule in Baden, and later worked with Carl Engler, also then at Karlsruhe. Under their influence, Haber became interested in the emerging field of physical chemistry and mastered the discipline despite never having studied it formally.

During his 17 years at Karlsruhe, Haber focused his research on the areas of thermodynamics and electrochemistry, and seemed to be naturally drawn to investigations that resulted in valuable industrial applications. At Karlsruhe, he moved up the academic ranks as he published three important books. His third book, The Thermodynamics of Technical Gas Reactions (1905), reported his early experiments into nitrogen fixation and established his reputation as an expert in the industrial applications of chemistry and chemical reactions in particular. It also led to his promotion to full professor, in 1906.

In 1911, Haber was appointed director of the Kaiser Wilhelm Institute for Physical Chemistry and Electrochemistry at Berlin-Dahlem. By then he had already successfully realized his objective of synthesizing ammonia. Although other scientists had earlier experimented with combining nitrogen and hydrogen, Haber used their work as a starting point to perfect his own process, and as such became, in 1909, the first to achieve a high-pressure industrial chemical reaction. After an associate, Carl Bosch, solved the practical problems involved in industrial production, the Haber-Bosch ammonia process came into wide-spread use and remains a standard method for large-scale ammonia production.

Although there was a great international need for nitrates as plant fertilizer, it was difficult to obtain because there was no economically feasible way to produce it in large amounts. The best source of nitrates was in a remote region of Chile, but Haber's process of synthesizing the nitrogen-hydrogen compound of ammonia made plant fertilizer suddenly available in abundance.

The synthesized ammonia could also be easily converted into explosives, and as World War I (1914-1918) began, Haber offered his expertise to the German government. Under his direction, the Institute produced so much explosive ammunition that it saved the German armies from surrender at a time when their munitions had nearly run out. Haber also oversaw experiments into chemical warfare, and his success in developing chlorine gas brought about approximately 15,000 Allied troop casualties, of which 5,000 were fatalities, when it was released experimentally on a battlefield on April, 22, 1915.

Though Haber was the 1918 Nobel laureate in chemistry, it was not until 1919, after the war, that he received his award. He had been specifically cited for the good his discovery had brought to the world, and he was deeply troubled when there was nevertheless an international outcry against his winning, because of his actions in the war.

Between the wars Haber worked on developing a process for extracting gold from seawater, which he hoped would help pay the massive postwar reparations the Allies had demanded of Germany. Although the endeavour failed, under Haber's direction, the Kaiser Wilhelm Institute became one of the world's greatest scientific research facilities, drawing an international group of brilliant minds from every discipline.

With the rise of Nazi power, all Haber's Jewish employees were forced to resign, and being a Jew himself, he resigned as well. He was offered haven at Cambridge University, but stayed only four months. Haber's contributions to scientific advancement, despite the controversy surrounding his war activities, were widely acknowledged and respected in his lifetime.

After Haber's death, German physicist Max Theodor Felix von Laue led an initiative to rename the Kaiser Wilhelm Institute in Haber's memory. It is now known as the Fritz Haber Institute.