Rome became the capital of the kingdom of italy after the comquest of?

Rome became the capital of the Kingdom of Italy after its conquest during the Italian unification, specifically in 1870. The Italian forces captured Rome from the Papal States on September 20, 1870, which marked the final step in the unification process, completing the Kingdom of Italy. This event symbolized the end of the temporal power of the Pope and the establishment of Rome as the political and administrative center of the newly unified Italy.