An Elvis impersonator sang “Are You Lonesome Tonight?” — addressing Jeremy Corbyn, the leader of the Labour Party, who had no coherent policy on Brexit. I met a man who told me he predicted Brexit as early as 1972 by analyzing verses from the Bible. He felt a mixture “of heart and intellect. Not just heart. Prior knowledge.” He spoke on and on, with barely a pause, like a man who had never been listened to before.

I had a serious conversation about post-Brexit trade negotiations with a man dressed as King Richard the Lionheart, but with silver Lurex where his chain mail ought to have been. He was carrying a placard that read, “Boris = BRINO” (Brexit in Name Only). It was proper that he was dressed for warfare, because he was awaiting another betrayal from the government. “I don’t believe that what Boris is doing is achieving a proper Brexit. But hopefully I’m wrong,” he told me.

As I walked down from the square toward Downing Street, the residence of the prime minister, I realized that I had not heard such a swath of regional accents in central London before; from people of various ethnicities and from all classes. Men in fine suits stood with working men and women from as far north as Cumbria, a county on the Scottish border.

What united everyone was an obsession with sovereignty: “I like to be able to choose who’s telling me what to do,” said one woman. “In the E.U. we’ve got no power.” “Our farming has gone,” said her friend, “our businesses. They tell us what we can farm, what we can do.” Then they lapsed into conspiracy theories: “They are like a dictatorship,” said the first woman, of the European Union. “Communists,” said the other, “it’s something like the same structure.”