The article gives an account of the historically significant, globally important contributions of Paul Walden (1863–1957) – the outstanding chemistry professor, substantive member of the science academies of seven different countries, honorary doctor of four universities, twice elected the director-rector of the Riga Polytechnical Institute (1902–1905 and 1917–1919). Since 1913, he has been nominated for the Nobel Prize in chemistry seven times, he is the pioneer of study of three new chemistry subsectors. In early 20th century, P. Walden was the most outstanding scientist of Latvian origin in the Riga Polytechnical Institute, he was a prominent organizer of higher technical education, and a skilled educationist. He was among the first faculty members, who by publishing his work in Russian science journals promoted the transfer of Western European democratic ideas to Eastern Europe. The article looks into the work of P. Walden at the time, when the institute was evacuated to Moscow, as well as during the re-evacuation period in Riga up to the establishment of the Latvian higher education establishment (University). The article is concluded with an account of the personality of the outstanding scientist of Latvian origin and his work in his homeland as well as at his Alma mater.