In the 1870s Italian army under the command of Raffaele Cadorna entered Rome, occupying Leonine City. Rome and Latium were also annexed to the Kingdom of Italy. In 1861, Rome declared the capital of Italy. These colorized pictures capture ancient landmarks, streets, towns, and famous monuments of Rome at the end of the 19th century. These photos were colorized using the photochrom process. This process was invented in the 1880s by a Swiss printer. A series of dyed limestone tablets were used to create a colorized black and white negative image. This technique was widely used to produce some of the earliest colorized pictures.