Passage: From the moment the three were grounded on 14 July, Strindberg's highly specialized cartographic camera, which had been brought to map the region from the air, became instead a means of recording daily life in the icescape and the constant danger and drudgery of the trek. Strindberg took about 200 photos with his seven-kilogram (15 lb) camera over the course of the three months they spent on the pack ice, one of the most famous being his picture of Andrée and Frænkel contemplating the fallen Eagle.Andrée and Frænkel also kept meticulous records of their experiences and geographical positions, Andrée in his "main diary," Frænkel in his meteorological journal. Strindberg's own stenographic diary was more personal in content, and included his general reflections on the expedition, as well as several messages to his fiancée Anna Charlier. All three manuscripts were eventually retrieved from the ice on Kvitøya in 1930.

Question: Who was Strindberg engaged to?
Anna Charlier