Few jackets have managed to cross as many style tribes—and decades—as the Harrington. In fact, if you were to enroll in Classic Menswear 101, the Harrington jacket would be a prerequisite.

And speaking of jackets, there’s one in particular that’s already stealing the show—the Suedette Relaxed Harrington Jacket, £59. If you want something warm enough for those unpredictable ...