My ticket takes me north out of Kings Cross, past the English countryside in spring’s warmth. For the journey—and most warm-weather travels—I bring this linen blazer: light, sharp, unstructured, with a touch of stretch. At York, I cross the River Ouse to meet Oliver at a pub. Impeccably dressed, he hands me a cloth-wrapped Roman coin. “Three-hundred A.D.,” he says. Oliver arguably has the greatest private collection of Roman Empire artifacts in western Europe. “Is that a fact?” I ask. “You’re holding it, you tell me.” Crafted from a three-season linen blend, with reinforced elbow patches and a removable throat latch.