1) The concept of federalism involves the division of powers between a central government and regional or local governments, allowing for shared governance and autonomy for different levels of administration.

2) The assassination of Archduke Franz Ferdinand of Austria in 1914 triggered the start of World War I.

3) The concept of separation of powers, as articulated by French philosopher Montesquieu, refers to the division of government responsibilities into distinct branches, such as the executive, legislative, and judicial, to prevent concentration of power.

4) The shortest scheduled commercial flight lasts just 1.7 miles and connects two Scottish islands, Westray and Papa Westray.