The Iberian Empire (1580-1640 AD), under Phillip II, a Habsburg, was a period when there was only one crown in the Iberian Peninsula. The 16th Century had been an Age of Discovery and Exploration for Portugal and Spain. By the end of the 16th century, shortly after the Iberian Union (Spain and Portugal, 1580-1640), the Iberian Empire comprised the whole Iberian Peninsula, most of Southern Italy including Sicily and Sardinia, Corsica, what is now Belgian territory, the 17 provinces of the Netherlands, small parts of France, Germany and Austria, all of South and Central America, Half of North America, Cape Verde, The Canaries, Madeira, The Azores, Cuba, Hispaniola, Puerto Rico and several Caribbean islands, the Portuguese African colonies of Angola and Mozambique, the Spanish African colonies, the Philippines, Goa, and parts of what are now India and Indonesia.

The first information I expect is an answer to "when were the British and the Iberian Empires at their peaks in terms of land area?" If the former was before 1755, one cannot include what was French Territory in North America. The latter can only have reached its peak some time between 1580 and 1640 which is the period when the Iberian Empire existed. By "largest" I mean in terms of land area, not political or military presence which was certainly more important under the British, during Victorian Age. Could the old maxim "The sun never sets on the British Empire" be applied to the Iberian Empire as well? Although short lived, was it at one time the largest empire ever?

from [wikipedia](https://en.wikipedia.org/wiki/Spanish_Empire) Illustration from Wikipedia (only the Illustration)

  • 3
    @MarkC.Wallace I have reopened the question. I would still say it's a matter of definitions, but rewording the title to "claimed area" means it can be reasonably answered by an answer exploring the aforementioned definitions. In terms of actually controlled areas, the Iberian Union obviously pales in comparison to the later British Empire, but claimed is a different ball game, and makes for a good question.
    – Semaphore
    Dec 24, 2017 at 20:26
  • 2
    @Centaurus: For one example, the map shows it claiming most of the US west of the Mississippi, and wester areas through Canada and into southern Alaska, when no Spaniard had ever been to those areas.
    – jamesqf
    Dec 25, 2017 at 18:28
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    @jamesqf Well, the British never had a reasonable control of Northern Canada and those hundreds of islands in the Arctic. In Australia, they settled on coastal regions but never controlled the Australian Outback. Not to mention the huge wilderness and jungle in Africa. South Africa was partly controlled by the Boers almost through the end of the 19th Century. I will be pleased to accept whatever you say if you answer the question with references and reliable links showing estimates of land area for each empire at their peaks.
    – Centaurus
    Dec 25, 2017 at 18:53
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    @Centaurus Depends on how you define "reasonable control" - it was more than the Iberians had in the Amazons, at least. Britain had a significant presence in North Canada, originally as the HBC, and evidently held enough control to impose tariffs on American gold speculators in 1862. Settlements in Australia were also way too far inland to be called "coastal" - Alice Springs (1872) is pretty much right in the middle of the continent. But, you're entitled to your views, of course. I would suggest, though, that making it so obvious that you want a certain answer dissuades potential answerers.
    – Semaphore
    Dec 28, 2017 at 16:55
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    Any discussion of British 'control' in the 19th century or earlier is irrelevant. The British Empire reached its largest extent in 1919. That area was 14,072,000 sq mi (‪36,446,312 sq km)‬. All defined by international borders. That's the target, (when and how big) to compare to.
    – justCal
    Dec 28, 2017 at 17:03

3 Answers 3


This question is a little more involved than it might appear, and has a few layers we need to tear through to solve. The basis is obvious, if the Spanish Empire was huge, and the Portuguese Empire at one time was responsible for vast exploration and colonization as well, then at a time when these two empires combined, might we have seen the worlds largest empire?

  • Did the Iberian Union(1580–1640), which combined the territories claimed by both Spain and Portugal, exceed in size the empire commonly accepted as the largest, the British Empire?

The first thing we can check is an entry listing the largest empires in Wikipedia. It gives some area numbers for each empire at its largest extent:

- British Empire        35.5 million km²    13.71 million mi²   23.84%  1920 

No entry for Iberian Union, but individually:

- Spanish Empire        13.7 million km²    5.29 million mi²    9.20%   1810
- Portuguese Empire     10.4 million km²    4.02 million mi²    6.98%   1815

At this point we can see that 24.1 million km² is way less than 35.5 million km², so question answered with one trivial visit to Wikipedia. But the page, even though it lists sources, does have a warning:

This section's factual accuracy is disputed.

So we need more information, or another way to tackle the question. The OP has a map from Wikipedia and a list of territories claimed at the time of the Iberian Union. It seems to show a huge amount of territory, and the distinction that we are looking into claimed territories is now part of the question definition.

Claimed can unfortunately be ambiguous as well, so perhaps a definition of Empire will help. Google gives us:

an extensive group of states or countries under a single supreme authority, formerly especially an emperor or empress.

The article providing our initial measurements says an empire is:

"any relatively large sovereign political entity whose components are not sovereign" and its size as the area over which the empire has some undisputed military and taxation prerogatives.

So from these definitions and the desire to qualify 'claimed' I will look at 'components' which have some form of definition as a political entity. Also to qualify as part of the Iberian Union these components must be defined(exist) within the time frame allotted: 1580–1640.

Most of the components in the list provided by the OP are relatively small, often well defined (islands) so not much debate concerning them. I will move on to the areas of contention, where most of the land mass lies, the Americas.

South America. The OP claims all of South America should fall into this empire, maps such as the one linked here show just a border region. If we look at treaties concerning the region, the Treaty of Tordesillas between Spain and Portugal split South America (and technically the world)

along a meridian 370 leagues west of the Cape Verde islands, off the west coast of Africa.

This essential split South America between the Spanish and the Portuguese. To qualify as part of the empire, we need to see a political structure, however, not just a 'claim', and this is seen here: enter image description here

Spain established political divisions covering all of South America not covered by Portugal. By the basis of 'claim' and the presence of a political structure, I would include all of South America.

North America. This is the tough spot. Irregular lines and anachronistic maps found all over wikipedia make this difficult. The real question comes down to how much of North America can be (claimed and having some political structure) included in the Iberian Union.

No real debate concerning the areas of the Caribbean, Mexico or Central America. This means we need to figure out Spanish territory North of Mexico. I've cropped and expanded the OPs' map showing this region : enter image description here

We can see extensive coverage by the Spanish Empire, but we need to look at dates. Spanish Louisiana looks huge, but:

Louisiana (Spanish: Luisiana) was the name of an administrative district of the Viceroyalty of New Spain from 1762 to 1802 that consisted of territory west of the Mississippi River basin, plus New Orleans. Spain acquired the territory from France,

This region was not part of the Spanish Empire during the time of the Iberian Union.

The upper region along the Canadian coast, the Nootka Territory, again dates show no political structure existed before the 18th century, so we can logically eliminate that region as a component of the Iberian Empire.

This leaves us with a 'fuzzy' border containing a region of the (now) western
United States, which may have fallen under undisputed claim by the Spanish during the Iberian Union, politically administered under the title of the Viceroyalty of New Spain.

The Numbers:

At this point, I believe we have narrowed the regions covered and the timing on most of the political structures to turn this into a geography question; add up the territories covered and compared to the British empire. I confess to getting much of the geographical info here just by googling, and have probably missed a few, but unless the figures are quite close I believe data covered will provide an adequate answer to the question.

European and African possessions:

Iberian Penninsula     ‪581,998 km²
Part of Italy          ‪301,337 km²
Sicily (25,711 km²‬),  Sardinia(‪24,089 km²‬),  Corsica(‪8,679 km²‬)
17 provinces of the Netherlands,        33,751 km²
small parts of France, Germany and Austria, (not itemized)
Portuguese Angola 1,246,700 km2, and Mozambique 801,590 km2
Cape Verde  4,033 km²,The Canaries 7,493 km², Madeira 800 km² ,the Azores 2,346 km²

subtotal=3,037,527 km²

New World & Pacific possessions:

South America  ‪‪     17,839,838‬ km²
Central America     507,967 km²
Mexico              1,964,247‬ km²
Cuba                108,780 km²
Hispaniola 76,179 km², Puerto Rico 9,103 km², Trinidad 5,130 km²
Philippines         343,448‬ km²

section total 20,854,692 km²

US region: (here to get a near approximation I will just combine the area of Florida and any state West of (and mostly west of) the western border of the Louisiana Purchase, as shown here. )

Florida 170,304 km², Louisiana 134,264 km² ,Texas 695,621 km²,
New Mexico 314,915 km²,Colorado 269,601 km²,Utah 219,887 km²,Idaho 216,630 km²
Arizona 295,254,Nevada 286,351,California 423,970

section subtotal 3,026,797 km²

So a grand total of 3,037,527 + 20,854,692 +3,026,797 = 26,919,016 km² ( ‪10,393,490 mi²)

Somewhat larger then the combined figures from the original wikipedia combined entry of 24.1 million km² , but not a challenger to the size of the British Empire at its greatest extent of 35.5 million km². A large enough difference that small discrepancies in any given value are not going to change the outcome.

So I conclude, from what figures and historical data I can find:

  • The Iberian Union was not larger then the British Empire.
  • 3
    Magna cum laude. Great research effort!
    – Centaurus
    Dec 29, 2017 at 20:56
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    For the Mongolphiles out there, 24.1 million km^2 is approximately equal to the peak of the Mongol empire.
    – Golden Cuy
    Jan 8, 2018 at 0:12
  • I think that the logic in this answer is flawed. According to the Treaty of Alcacovas in 1479 Portugal claimed all lands and seas south of Cape Bojador which is many hundreds of miles north of the equator, and so Portugal claimed more than half the world. The treaty of Toresillas divided the world into hemispheres to be explored and colonized by Spain and Portugal. Together they claimed all of the Americas as well as Siberia, China, India, Africa, etc. So the areas claimed by Spain and Portugal - and the OP said claimed - were much larger than the British Empire.
    – MAGolding
    Nov 23, 2018 at 21:02
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    @MAGolding I do cover that in this answer, specifically to be considered part of an 'empire' there needed to exist a political structure, not just a 'claim'.
    – justCal
    Nov 23, 2018 at 22:34
  • 1
    The research about the Iberian Union in the answer is great, but there should be a at least a bit of research to check Wikipedia numbers on the British Empire.
    – Pere
    May 14, 2019 at 18:16

We are forgetting that in times of the Iberian Union, not only lands were claimed, but also oceans and seas according to the "Mare Clausum" policy (closed seas belonging to a certain power and with forbidden navigation to all others). Those claims are also shown in the OP map, but I will add another one here:

enter image description here

A French nobleman, Duplessis-Mornay, once said: "The ambition of the Spaniard, which has overleaped so many lands and seas, thinks nothing inaccessible.”

It was only in 1609 when the thinker Hugo Grotius started to argue against this policy with his "Mare Liberum" concept, which is the principle that we follow even today (international waters).

But back then, Núñez de Balboa claimed the entire Pacific Ocean for the King of Spain in the 1510s, and that claim was kept by Spanish authorities until 1790, when they finally accepted free navigation in the Pacific in the Nootka conventions.

So that would add all the explored surface of the Pacific Ocean to the Spanish Empire, potentially 140 millions km2.

Besides that, Portugal did the same with the South Atlantic (south of Cape Bojador, according to Treaty of Alcaçovas) and the Indian Ocean, which Afonso de Albuquerque sized in a master plan to convert it into a Portuguese mare clausum, conquering Hormuz, Aden, Malacca and Mozambique. Those seas add another good 100 million km2 into the count. These claims were inherited in times of the Iberian Union, but neglected and finally destroyed by expeditions of other nations in the 17th century.

To sum up, in the mind of a Spanish or Portuguese governor or diplomat in the 1590s, all these seas were part of the Spanish empire. So we have a gargantuan possible maximum of 270 million km2 - yes, two hundred and seventy million - (145+100 million km2 of those oceans plus 25 million in land), which is over seven times the size of the British Empire, which never claimed entire seas as only British (though it "de facto" controlled many of them during the Victorian era). Even if we downsize these numbers because of the impossibility of exact measurement of how much of the sea was actually controlled, they show how different empires are in different eras, so I wouldn't conclude so easily that the British one was larger.


Only a short answer I'm gonna give here, showing the usual flaw or pro-British bias in all these analysis.

When talking about Imperial Extensions, usually the Spaniards, Portuguese and even the French (until the XIX century) are very reasonably honest because they show the territories that actually were under their control and undisputable possession, that is, territories they really owned. An example of this would be the Spaniards when they talk about Philippines: the entire Oceania, Polynesia and Melanesia was under their military control and influence in the XVII Century but you will never find a Spaniard's map claiming they "owned" everything in those regions. They only talk about their real possession in the Philippines and that's it. Another example could be the French, they never say "the ENTIRE Canadá was ours" because it's not true, they only owned the eastern coastal line of Canadá and the inner parts of Maryland and Louisiana.

On the other hand, the English always faking news (you can even imagine them with a pirate voice saying "arrggh the entire Canadá was ours"), present images of their alleged possessions which in fact, are merely based on nowadays modern polítical territories of those places and NOT in what they actually possessed in terms of real territory under their control. The British never, never owned the ENTIRE Canadá, for example. Now, if we consider "owning" a territory giving an trading patent to a certain company (i.e. Rupert's Land), the Spaniards and Russians also had a lot of commercial lines in those places and they could claim those territories as their own in the same way. Even the French had their own companies exploiting many of those places with Royal Patents and they never marked those territories as part of their Empire. If you see ancient Spaniard and French maps, they always mark those places as "unchartered/non possessed territories" and that is simply being honest because they could easily do the same thing as the English and claim it their own.

Only the British do that, and it is intelectual dishonesty to say the least. Same happened in the Scramble for África, none of the world powers who shared that continent never, ever controlled what they claimed to control based on those maps.

Being all that said, it's very possible that the Habsburg Iberian Union was the largest Empire based on REAL possession of territories, with the exception of the MONGOLS.

  • 5
    Lots of opinion (much of which I suspect is off by a century or more from any factual basis) and no verification or sources given for said opinion. Sep 8, 2019 at 18:58

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