B1: America: from new nation to divided union, 1783–1877

B2: Changes in medicine, c1848–c1948

B3: Japan in transformation, 1853–1945

B4: China: conflict, crisis and change, 1900–89

B5: The changing role of international organisations: the league and the UN, 1919–c2011

B6: The changing nature of warfare and international conflict, 1919–2011