Vladimir Igorevich Arnol'd, one of the greatest mathematicians of the past century, died on 3 June. Professor Arnol'd worked at the Steklov Mathematical Institute in Moscow and at Paris Dauphine University up until his death. He visited ICTP regularly each year over the years 2006-2009, when he delivered series of seminars on his fields of research. He was also course organizer of the College on Singularity Theory in 1991.

Arnol'd is best known for the Kolmogorov–Arnold–Moser theorem regarding the stability of integrable Hamiltonian systems. He made important contributions in a number of areas including dynamical systems theory, catastrophe theory, topology, algebraic geometry, classical mechanics and singularity theory.

He also won many prestigious international awards for his research, including the Wolf Prize in 2001.