The unification of Saudi Arabia was a 30-year-long military and political campaign, by which the various tribes, sheikhdoms, and emirates of most of the Arabian Peninsula were conquered by the House of Saud, or Al Saud, between 1902 and 1932, when the modern-day Kingdom of Saudi Arabia was proclaimed. Carried out under the charismatic Abdul Aziz Ibn Saud, this process created what is sometimes referred to as the Third Saudi State, to differentiate it from the first and second states that existed under the Al Saud clan.