Principality of Liechtenstein (modern, with crown)
Who & why: after discovering at the 1936 Berlin Olympics that Liechtenstein's plain blue-and-red flag was identical to Haiti's, the principality adds a gold princely crown to the canton in 1937 to distinguish it. Liechtenstein stays neutral through both World Wars, joins the UN only in 1990, and today runs one of the world's highest per-capita incomes on finance, industry, and (fittingly, given its 1719 origin) a still-reigning princely house.
What it represents: the blue-over-red bicolour with a gold princely crown in the blue stripe near the hoist, added on 24 June 1937 (Wikipedia and Flags of the World agree) after the confusion with the Haitian flag at the 1936 Olympics. Flags of the World adds that the crown was modified in 1957 and again in 1982 (Wikipedia's infobox gives 30 June 1982), so the 1937 flag is the first with a crown, not the current form.
Wikipedia's text says the crown was added on 24 June 1937; its infobox gives 30 June 1982 for the current version. FOTW's history page (after Baert) says a yellow prince's bonnet was added in the blue stripe near the hoist on 24 June 1937 after the confusion with the Haitian flag at the 1936 Berlin Olympics, with the crown modified in 1957 and again in 1982, and its law page quotes Joseph Hoop's 1937 presentation of the flag.
- Flag of Liechtenstein — Wikipedia compiled
- Liechtenstein (Flags of the World) — Flags of the World (CRW Flags) compiled
- History of the National Flag of Liechtenstein — Flags of the World (CRW Flags) compiled
- Liechtenstein Flag Laws — Flags of the World (CRW Flags) compiled
Not established: The crown's shape changed in 1957 and 1982, so 'unchanged since 1937' holds for the blue-over-red bicolour with a crown, not the crown itself. Design and swatch colours not checked against a specification.