Imperialism has two meanings, one escribing an action and the other describing an attitude. Most commonly it is understood in relation to Empire building, as the forceful extension of a nation's authority by territorial conquest establishing economic and political domination of other nations. In its second meaning the term describes the imperialistic attitude of superiority, subordination and dominion over foreign people. Imperialism is often autocratic, e.g. in early 20th century Japan, and sometimes monolithic in character. While the term imperialism often refers to a political or geographical domain such as the Ottoman Empire the British Empire, or the Russian Empire, etc, the term can equally be applied to domains of knowledge, beliefs, values and expertise, such as the empires of Christianity (see Christendom) or Islam (see Caliphate).