The world’s first combat photographs were taken during the American-Mexican War of 1846-1847 by an anonymous photographer. The world’s first known combat photographer was Romanian Carl Baptiste de Szathmary (1812-1887), who took his camera to the Crimea a year before more famous Roger Fenton arrived two years later. In 1853, he was documenting the conflict between Russia and Turkey over Wallachia and other Rumanian territories which would eventually devolve into the Crimean War.
Although the Turks once assailed his wagon, thinking he was a Russian spy, he managed to photograph various troops, both Turkish and Russian, and their commanding officers. When the Turks occupied Bucharest, he managed to get a photosession with their commander Omar Pasha (although Fenton’s photo of Omar Pasha would later become more famous).
He exhibited these 200+ photos at the Paris Exposition in 1855 and presented them to the royals of Europe. Queen Victoria and Prince Albert met him, saw his photos and later dispatched Roger Fenton to Crimea). No copies of his albums survived, and his work lives on only in a handful of photos scattered here and there. See the list here. Like Fenton’s, his own career as photographer was short. Trained as a painter, he later became the official painter of the Romanian rulers. After 1860, although highly celebrated and decorated by the European courts from Moscow to Württemberg, he produced only chromolithographs. In 1866, he was made the Photographer to the Court of Romania, and as one he quietly passed away, his glory days well past.