The international law principle of hot pursuit is comparable in certain respects to the common law principle, but was probably conceived independently. It began to coalesce into a general custom of international relations during the early years of the 20th century, although the general principle had been advanced before in national legislation such as the British Hovering Acts. The participating states at the League of Nations Codification Conference of 1930 broadly agreed on the validity of the right of hot pursuit, but the proposed convention on territorial waters in which it was included was never ratified. It was finally codified as Article 23 of the Geneva Convention on the High Seas in 1958.