Three stripes stacked on top of each other. This is the older of the two tricolour formats, predating the French Revolution and rooted instead in older heraldic traditions, dynastic colors, and naval flags that needed to be read easily at a distance and from the side.
The Netherlands carries one of the oldest examples, its orange-white-blue Prince’s Flag dating to the late 1500s, with orange eventually swapped for red. Germany’s black-red-gold goes back to 19th-century liberal and nationalist movements, later becoming the flag of a unified, democratic Germany after World War II. Russia’s white-blue-red, adopted under Peter the Great and modeled partly on the Dutch flag, went on to influence the Pan-Slavic colors used by several other Slavic nations.
Below, every country flying a horizontal tricolour, linked through to the story behind its specific colors.
Botswana · Egypt · Eswatini · Ethiopia · Gabon · Gambia · Ghana · Niger · Rwanda · Sierra Leone · Austria · Bulgaria · Croatia · Estonia · Germany · Hungary · Latvia · Lithuania · Luxembourg · Netherlands · Russia · Serbia · Slovakia · Slovenia · Spain · Armenia · Azerbaijan · Cambodia · India · Iran · Iraq · Laos · Lebanon · Myanmar · North Korea · Syria · Tajikistan · Thailand · Uzbekistan · Yemen · The Bahamas · Costa Rica · El Salvador · Honduras · Nicaragua · Argentina · Bolivia · Colombia · Ecuador · Paraguay · Suriname · Venezuela