On Wednesday, March 12, 2025, Dennis Gaitsgory (Max Planck Institute for Mathematics, Bonn) held lecture titled „Proof of the geometric Langlands conjecture“ as part of Department of Mathematics Colloqium „Sibe Mardešić“ . Dennis Gaitsgory is among the leading mathematicians of today, whose work centers around the geometric Langlands program. Prior to his current position as a director at the Max Planck Institute for Mathematics in Bonn, he was a professor at Harvard University and Israel Gelfand Chair at IHES. He has been awarded the prize of the European Mathematical Society and the Chevalley prize in Lie theory for his work. He is a member of the National Academy of Sciences and has mentored 12 PhD students. As a part of his ongoing efforts in bringing more visibility to the geometric Langlands program, he coauthored a 1425-page book together with J. Lurie and N. Rozenblyum. Since Department of Mathematics Colloqium „Sibe Mardešić“ has been founded, 16 renowned mathematician visited us and held lectures a s part of the Colloquium. We are happy and honored that we are able to organize cooperation with leading mathematicins of today.