As the title suggests, this book is about the personal and social relationships that govern the global economy. I wanted to tell a story of global finance that focuses not on markets or faceless institutions, but on people. We often imagine the financial system as data, models, and cold rationality. Yet again and again, in moments of crisis—from the interwar years to the 2008 meltdown, and even the 2020 Covid-19 fallout—I found that what truly keeps the system from unraveling is far more human: trust between central bankers.The book traces how relationships quietly built over years—through late-night calls, frequent meetings, and crises weathered together—shape how central bankers respond when panic strikes. Countries rely on one another’s central banks for emergency lifelines, called swap lines, which keep dollars and other currencies flowing. Who gets help, and on what terms, depends less on treaties or rules than on whether the individuals involved actually trust each other. Where trust exists, cooperation is swift and generous. Where it doesn’t, countries can find themselves isolated just when support is most needed.Through a century of financial upheavals, I show how these social ties repeatedly prevent deeper collapses. But not everyone is included. Some central banks, especially in emerging economies, remain on the outside, leaving them more vulnerable and slowing recovery.At its heart, Bankers’ Trust is about a system that depends on human connection but operates largely out of view. Trust is the invisible glue holding it together. It can avert collapse—but it also highlights how fragile and personal our supposedly impersonal financial world really is.