What is Lester B. Pearson?
{{Infobox Prime Minister | honorific-prefix = [[The Right Honourable]] | birthname = Lester Bowles Pearson | honorific-suffix = {{postnominals|country=CAN|size=100%|PC|OM|CC|OBE|}} | image = | caption = Pearson in 1957 | office = 18th [[Prime Minister of Canada]] | term_start = {{start date|1963|4|22|df=y}} | term_end = {{end date|1968|4|20|df=y}} | monarch = [[Elizabeth II]] | governor_general = [[Georges Vanier]]<br>[[Roland Michener]] | predecessor = [[John Diefenbaker]] | successor = [[Pierre Trudeau]] | office2 = Leader of the [[Liberal Party of Canada]] | term_start2 = {{start date|1958|1|16|df=y}} | term_end2 = {{end date|1968|4|6|df=y}} | predecessor2 = [[Louis St. Laurent]] | successor2 = Pierre Trudeau | office3 = [[Leader of the Official Opposition (Canada)|Leader of the Opposition]] | term_start3 = {{start date|1958|1|16|df=y}} | term_end3 = {{end date|1963|4|22|df=y}} | monarch3 = Elizabeth II | primeminister3 = John Diefenbaker | predecessor3 = Louis St. Laurent | successor3 = John Diefenbaker | office4 = 8th [[Minister of Foreign Affairs (Canada)|Secretary of State for External Affairs]] | term_start4 = {{start date|1948|9|10|df=y}} | term_end4 = {{end date|1957|6|20|df=y}} | primeminister4 = [[William Lyon Mackenzie King|W. L. Mackenzie King]]<br>Louis St. Laurent | predecessor4 = Louis St. Laurent | successor4 = John Diefenbaker | order5 = 2nd | office5 = List of Canadian ambassadors to the United States{{!}}Canadian Ambassador to the United States | term_start5 = 1944 | term_end5 = 1946 | primeminister5 = W. L. Mackenzie King | predecessor5 = [[Leighton McCarthy]] | successor5 = [[H. H. Wrong]] | order6 = 8th | office6 = President of the United