Denmark
What the source says
Referenced, awaiting primary-source reviewAn origin legend connects the introduction of the flag to the Battle of Lindanise of 1219 [the flag falling from the sky]. The Nordic cross represents Christianity. The flag holds the Guinness world record of being the oldest continuously used national flag, that is since 1625. The elongated cross design was subsequently adopted by other Nordic countries: Sweden, Norway, Finland, Iceland, and the Faroe Islands.
Referenced, not verified: a secondary work states this, and the document that constitutes the flag has not been read for this entry. What the marks mean.
Colors and meaning
Symbolism and history(r1)
The Dannebrog, a white Nordic cross offset toward the hoist on a red field, holds the Guinness record as the oldest continuously used national flag (since 1625); its elongated cross design was subsequently adopted by Sweden, Norway, Finland, Iceland and the Faroe Islands.
Most similar flags
The 6 closest of the 194 other national flags, ranked by a similarity index computed from the flag images themselves. The number is that index, 0–100 — not a claim that the two flags are “X% identical”.
Switzerland90near-identical colour proportions.
Tunisia88near-identical colour proportions.
Tonga87near-identical colour proportions.
Norway86the same colours in similar amounts.
Türkiye86the same colours in similar amounts.
Morocco82the same colours in similar amounts.
Computed at build time: each flag is rasterised to 64x48, and the score is 0.55 × colour overlap + 0.45 × structure. A different weighting would rank these differently. How the index works.
References — not verification
(r1) Referenced to Dannebrog (Wikipedia (English)) on 2026-07-17. States the adoption year, which colors the flag has, what the colors mean and the symbolism and history on this page. The passage it states them in is quoted at the top of this entry.
Further reading: Dannebrog on Wikipedia
