How big was Gondor's army?

This is a departure from my usual content. I am a big Lord of the Rings fan. There are a number of Substacks and Youtubes devoted to Tolkien’s works that mostly deal with it from a literary or religious/philosophical point of view. But there are other aspects of interest to some readers that are less well covered. In one of his letters¹ Tolkien relates having received an “appalling mass” of letters from such readers and comments on

the curious effect that a story has, when based on very elaborate and detailed workings, of geography, chronology and language, that so many should clamor for sheer “information” or “lore.”

In another letter¹ he reports:

While any like you demand maps, others wish for geological indications rather than places,…Musicians want tunes, and musical notation; archeologists want ceramics and metallurgy…historians want more details on the social and political structure of Gondor.

Interest in more details about the imaginary world Tolkien created dates back to the very beginning. In this spirit I offer my own contribution: estimates of the size of Gondor’s armed forces and of the populations of Rohan and Gondor. All of the page references below come from my edition² of the The Return of the King. Quotes from this text are given in italics.

How large was the force Aragorn gathered in the south of Gondor?
The sighting of Aragorn’s fleet on March 15 is recorded on page 149: they beheld a fleet borne up on the wind, dromunds, and ships of great drought with many oars, and with black sails bellying in the wind. The description mentions two kinds of craft, dromunds and great ships, both of which had oars as is clear from the text on pages 187-8 (this is on the morning of March 14) “It is forty leagues and two from Pelargir to the landings at the Harlond” he [Aragorn] said. “Yet to the Harlond we must come tomorrow or fail utterly.” The oars were now wielded by free men, and manfully they laboured; yet slowly we passed up the Great River…we had no help from wind. There was no wind for the first ~20 hours of the journey, but then the wind picked up and they made better time.

The term dromund likely refers to the dromon, a medieval Byzantine galley that according to Wikipedia came in three sizes, a small galley crewed by around 100 men, a larger one crewed by around 150 men and a heavy dromon crewed by 230 rowers carrying 70 marines. Scaling by the number of rowers I will assume the smaller ships carry 30 and 45 troops, respectively.

The text on page 186 describes the Corsair fleet as 50 great ships and smaller ships beyond count, some of which had put off.  It says that to each great ship that remained Aragorn sent one of the Dunedain. On page 187 it says Aragorn chose the greatest ship to be his own. Page 55 describes the arrival of Halbarad and 30 Dunedain in Rohan. With Aragorn this gives a total of 32 Dunedain. Since Aragorn sent one of the Dunedain to each of the great ships captured and took one himself, this means not more than 32 of the great ships were captured by Aragorn.

I will assume that the black fleet originally consisted of the 50 great ships (heavy dromons) with an equal number of small and medium galleys, for a combined troop capacity of 7250 men (50x70 + 50x45 + 50x30). With them were troop transports and supply ships, numbering beyond count. The transports and supply ships would be equipped with sails only and lacking oars, would only arrive after the battle.

Since the text refers to some (rather than most) of the ships having escaped, I assume that Aragorn captured more than half (55%) of the galley fleet on March 13, enough to carry about 4000 men. This was the force that arrived with him mid-day on March 15 at the Harlond, which is described on page 150 as a great valour of folk of Lebennin and Lamedon and the fiefs of the South.

Additional reinforcements were dispatched by Aragorn to follow him upriver; many were bidden to follow me up the river in any craft they could gather and with this wind they shall soon be at hand, indeed, several ships have already come to the Harlond (p193). These would be the sail-powered troop transports that could not travel until the wind arrived in the pre-dawn hours on March 15 and would arrive over the next couple days. Other reinforcements were sent by land; four thousands I sent marching from Pelargir through Lossarnach two days ago’ and Angbor the fearless rides before them (p193). These would make the 200 km journey in five days arriving on March 18 just after the Host of the West left Minas Tirith.

So far, I estimated the size of the galley-borne force that went with Aragorn and fought in the battle of Pelennor Fields at about 4000 men, to which I add Angbor’s army of 4,000 to make 8,000. I further assume that the number of men making the journey upriver on the captured sailing vessels also numbers around 4,000 and add this to give a total of 12,000 brought to Minas Tirith by Aragorn.

What the composition of the force sent to Mordor suggests
From the forces available to them, the Captains of the West assembled 7,000 troops for the assault on Mordor (page 193). This force was composed of 3,500 from the Minas Tirith garrison, 2,000 from the troops Aragorn had gathered, 1,000 from the Rohirrim, and 500 additional cavalry. This last group would include the elite forces of the Dunedain, Prince Imrahil’s company of cavalry, plus Aragorn and the sons of Elrond. I assume Imrahil’s cavalry numbers around fifty and combined with the others makes up 80 out of the 500-man force with the remaining 420 drawn from other Gondorian forces.

The Rohirrim force going to Mordor was one-sixth of the initial force of 6,000 Riders. Applying this ratio to the 3,500 drawn from Minas Tirith suggests an initial garrison of 21,000 men. The “rule of six” applied to the 420 drawn for the elite cavalry come from a pool of 2500 Gondorian troops I have not yet acknowledged. These would be the soldiers from the outlands described on pages 49-50. Tolkien gives explicit numbers for 2100 men plus Imrahil’s company of horsemen and some others for whom no exact numbers are given, but sums it up with that was all, less than three thousands full told. No more would come. A figure of 2500 for the outlands contingent seems reasonable. Finally, the 2,000 Aragorn provided are one-sixth of the 12,000 estimated in the previous section.

This gives the components of the Western side in the battle as 21,000 initially present at Minas Tirith, 6,000 from Rohan, 2500 from the outlands, and 4000 arriving with Aragorn for a total of 33,500. Tolkien reports that the remaining effective Rohirrim numbered about 4,000, of which 1,000 went to Mordor and the rest went with Elfhelm to deal with an unfought remnant from the invasion. This suggests about one-third casualty rate from the Battle of the Pelennor Fields, with two-thirds remaining combat-ready.  Two-thirds of the initial 33,500 men is 22,000 effective fighters after the battle. To this are added the 8,000 sent north by Aragorn who arrived after the battle, for a total of 30,000. From this total Aragorn figures I judge we could lead out seven thousands, horse and foot, and leave the City in better defense than when the assault began. Subtracting 7000 from the 30,000 leaves 23,000, which is indeed more than the original garrison of 21,000. This checks out.

Summing up the troop numbers
So far I have accounted for 21,000 troops initially at Minas Tirith and 14,500 coming from the rest of Gondor, 2,500 before the battle, 4,000 during the battle and 8,000 after. Tolkein notes that Minas Tirith was not receiving all the reinforcements that could have been sent. During the description of the arrival of the forces from the outlands on page 49 disappointed onlookers note the paucity of the aid and speculated as to why: We hoped for ten times the number. That will be the new tidings of the black fleet. They are sparing only a tithe of their strength. Taken literally, this implies that the 2,500 I estimated that arrived that day were but a tenth of 25,000 who could have come.

But after the black fleet was defeated and more reinforcements dispatched, the total sent was 14,500, not 25,000. Were the onlookers exaggerating and the available forces were actually less than they believed, or were the southern fiefs still holding back? I used to think that the idea of 10-fold greater manpower reserves available in the outlying regions of Gondor was an exaggeration. But a closer look for this post suggests something else.

When Gondor appeals to Rohan for aid, Theoden responds as follows (p 87): Ten thousand spears I might have sent riding over the plain to the dismay of your foes. It will be less now, I fear, for I will not leave my strongholds all unguarded. Yet six thousands at least shall ride behind me. Despite the destruction of Saruman’s power, Theoden felt it necessary to hold back two-fifths of his deployable forces against the possibility of further invasions. Indeed, the Tale of Years (p 467) records that eastern Rohan was invaded on March 11, while Theoden was making the 500 km journey to Gondor. As it turned out the invaders were destroyed by the ents on the next day but had this not happened and Theoden taken all his forces with him, great harm would have come to his country.

It is entirely possible that the Southern fiefs, having defeated one invading force because of a one-time supernatural intervention, feared the possibility of a second attack and like Theoden did not send their full strength to Minas Tirith. This seems prudent to me. Recall that a fraction of the black fleet had escaped. Fearing the wrath of Sauron if they returned home unsuccessful, a reasonable alternative for them might be piracy. Leaders of the southern fiefs would need to have some forces to deal with this threat.

If I assume they held back roughly the same fraction as Theoden, the 14,500 troops sent to Minas Tirith, came out of a total of about 25,000 men. With this new calculation, it seems the onlookers were right, the outlands initially sent only a tenth of what they had due to fear of the Corsairs.

With this Gondor’s forces total to 46,000, 21,000 stationed in the capital and another 25,000 in the surrounding lands.

Further insights gained from these calculations
In 1066 the last Saxon king of England, Harold Godwinson, brought a force of ca. 15,000 to the Battle of Stamford Bridge to deal with the invading army of Norse King Harold Hardrada. The population of England at that time has been estimated between 1.2 and 2 million. I favor a figure of 1.5 million. Given that Rohan’s army of 10,000 is about two-thirds the size of Harold’s force, I estimate Rohan’s population as two-thirds that of Harold’s England, or about one million. Rohan is about 42,300 sq miles in area. Hence Rohan has a population density of about 24 persons/sq mi, compared to about 30 for England in the 11^th century.

Gondor’s larger army size suggests a population of around 4½ million. Gondor’s area is about 87,500 sq. miles, implying a population density of about 50 persons per sq. mile, which is about the same as England in the mid-12^th century. This is consistent with the portrayal of Gondor as the more advanced civilization compared to Rohan.

1. Unfinished Tales, Ballantine Books First edition (1988) 8^th Printing Apr 1992, page 2.

2. Return of the King, Ballantine Books First edition (1965)  73^rd Printing Apr 1984.