Flags Through History: A Timeline

The earliest identifiable military standards weren't fabric at all. Egyptian and Assyrian forces carried rigid, carved emblems mounted on poles — representations of deities, animals, or rulers — used purely as visual rally points so scattered troops could find their own unit in the field. There's no evidence these objects carried anything resembling a modern flag's civic or national meaning; their entire function was locational.

Cloth banners only became practical once textile production could reliably produce large, durable, brightly dyed fabric sections — a manufacturing threshold, not a design idea, is what separates this earliest period from everything that follows.

Roman legions carried the vexillum, a cloth square hung crosswise from a horizontal bar rather than flown loose — a detail that later gave vexillology its name — alongside the aquila, a solid gold eagle standard unique to each legion and guarded with what amounted to religious devotion. Roman military record-keeping treated the capture of a legion's eagle as a serious, documented disgrace, evidence these objects functioned as something closer to a unit's honor than mere equipment.

This period is the last one in which flags remained almost entirely a military tool, with essentially no civilian, religious, or national dimension attached to them at all.

Medieval Europe developed heraldry as a formal visual system — specific colors, shapes, and charges assigned to specific noble families and later to territories, with rules governing how those elements could combine. Portugal's flag history traces some of its oldest heraldic elements, including the shield and castles device, back to this medieval period, layered and modified repeatedly over subsequent centuries as the kingdom's territory and dynastic fortunes changed.

This is also the period that gave flags their first real grammar: once heraldry established that a color or shape could mean something specific and inheritable, the idea that a flag's design elements should each carry deliberate meaning — still a core design principle today — had its origin.

European naval expansion introduced a genuinely new function for flags: marking a ship's registered nationality at sea, where visual identification from a distance had real legal and military consequences, and physically planting a flag onshore as an act of territorial claim. Spain's and Portugal's respective royal ensigns during this period functioned less as symbols of shared citizenship and more as legal markers of crown ownership over ships, ports, and claimed land — a use of the flag closer to a modern trademark than to a national emblem.

This period also produced the earliest formal distinctions between naval war ensigns and separate merchant-ship flags in several seafaring nations, a split covered in more detail in our national-flag-vs-civil-ensign guide, and one still preserved today by a handful of countries with long maritime traditions.

A wave of new political thinking across this century treated a flag's proper owner as the citizenry rather than a monarch — a shift most sharply visible in the flags adopted by newly unifying nations. Germany's path illustrates how gradual this could be: the black-red-gold combination first spread as a volunteer military unit's colors during the Napoleonic Wars, gained political weight at an 1848 assembly seeking German unification, and only became the settled flag of an actually unified German state in 1871, more than half a century after the colors first appeared.

Japan's own flag standardization sits at the tail end of this same century, for a genuinely different reason than Europe's citizen-versus-crown shift: the sun-disc design had older regional use, but it was only formally adopted as the country's national flag by government order in 1870, during the Meiji era's broader push to present Japan as a modern nation-state on equal footing with Western powers — flag standardization here functioning as part of a deliberate international-legitimacy project rather than a domestic political revolution.

By the close of this period, most of Europe had shifted from flags representing ruling families to flags representing nations as political communities — a change in what a flag was legally and symbolically for, not merely a change in which colors were fashionable.

The mid-20th century produced the highest volume of brand-new national flags in recorded history, as colonial rule across Africa and Asia ended and each newly sovereign state needed its own flag, typically within a short window around its independence date rather than after years of deliberation. A second, smaller wave followed the Soviet Union's 1991 dissolution, but with a different character: several of the newly independent states in this second wave reached backward, restoring flags from earlier, shorter periods of independence rather than commissioning anything new — reuse of history rather than invention.

Full national flag replacements have become genuinely uncommon since the early 1990s, and the ones that do happen tend to be well documented, deliberate, and specific rather than incidental. Mauritania's 2017 addition of red stripes to a flag otherwise unchanged since 1959, meant to represent the sacrifice of the independence struggle, is a useful marker of how modest and targeted modern flag adjustments tend to be, compared to the wholesale mid-century redesigns of the decolonization wave a few decades earlier.