Benjamin Sumner Welles III (1892-1961), commonly known as Sumner Welles, was an influential American diplomat and foreign policy advisor to President Franklin D. Roosevelt. Born on October 14, 1892, in New York City to Benjamin Sumner Welles Jr. and Frances Wyeth Swan, he came from a prominent New England family with deep Puritan roots, tracing lineage to Boston merchants and related to Senator Charles Sumner, after whom he preferred to be called. Welles rose quickly in diplomatic circles, serving as U.S. Ambassador to Cuba amid political unrest, becoming Assistant Secretary of State in 1933 where he architected the 'Good Neighbor' policy toward Latin America, and appointed Under Secretary of State from 1937 to 1943 (sources vary slightly on start year between 1936-1937), acting as FDR's key advisor on foreign affairs during critical pre-WWII years. Welles played a pivotal role in shaping U.S. hemispheric relations and briefed organizations like the World Jewish Congress on policy matters. His tenure ended amid personal scandals and political intrigue, after which he transitioned to writing, including non-fiction works on international affairs. He broke his health in service to Roosevelt and succumbed to the rigors of public life shaped by his family's austere heritage. Welles died on September 24, 1961.