RUGBY, England—Stuart Field raised his first flags in July: the English red cross of St. George and also a smattering of the British red, white and blue, hanging them from his hometown’s streetlights.

An estimated 110,000-150,000 people marched at a "Unite the Kingdom" protest against immigration in London on September 13, according to official figures from the city's Metropolitan Police. The event ...

In the weeks after the terrorist attacks of September 11, 2001, the American flag began appearing in places where it had never been seen before. Suddenly, the stars and stripes were everywhere: ...