Stained-glass window V26 was commissioned by the Fabbrica at the beginning of the 20th century to mark the occasion of the third centenary since the canonisation of Archbishop Charles Borromeo (1610). The work summarises the life of Borromeo across nine sections, and the following episodes can be seen from bottom to top in which the Saint: Distributes Bread to the Poor of Arona, Reassembles the Vatican Academy, Is Made Cardinal, Enters Milan as Archbishop, Convenes the Provincial Councils, Founds Religious Orders, Discusses Plans for the Cathedral with Pellegrino, Helps Victims of the Plague, and The Saint's Funeral. The window, located in the Duomo's northern transept, is the unanimous work of four artists: Giovanni Beltrami, Giovanni Buffa, Guido Zuccaro and Innocente Cantinotti. The stained-glass window was the subject of a complex restoration concluded in 2020 by Laura Morandotti and made possible thanks to the support of Fondazione Cariplo's Beni al sicuro project. The main reasons that rendered necessary the restoration were the poor condition of the marble elements, as well as the deterioration of the glass's painted surface: the preliminary study of the doors had in fact shown that the window was mostly cold painted, which was why it was necessary to anneal the panels.