Dmitri Ivanovich Mendeleev was born on 8 February 1834 in Verkhnie Aremzyani, Siberia, into a large family facing significant hardship. His father, a teacher, went blind and died during Mendeleev’s childhood, leaving his mother to support the family by running a glass factory. Despite these challenges, she was determined to secure her son a strong education and took him across Russia to find suitable schooling.

As a young man, Mendeleev studied at institutions in Tobolsk and later Saint Petersburg, where he developed a deep interest in chemistry. His academic talent led him to become a professor and researcher, focusing on solutions, petroleum, and chemical theory. His doctoral thesis, completed in 1865, explored the behaviour of alcohol–water mixtures, reflecting his early fascination with the structure of matter.

Mendeleev’s most enduring achievement came in 1869 when he formulated the periodic law and created the first widely recognised periodic table. By arranging elements according to atomic weight and identifying repeating patterns, he not only organised known elements but also predicted the existence and properties of several undiscovered ones, such as gallium and germanium. The later discovery of these elements confirmed the power of his system and secured his legacy as one of chemistry’s foundational figures.

Beyond his scientific work, Mendeleev was known for his prolific writing, including the influential textbook Principles of Chemistry. He received numerous honours, such as the Davy Medal and the Copley Medal, and remained active in scientific and industrial research throughout his life. Mendeleev died on 2 February 1907 in Saint Petersburg, leaving behind a transformative scientific legacy that continues to shape modern chemistry.