Hi there!

First off, I would like to apologise, I am typing this up on a viciously bumpy train journey, and I don't have access to a lot of sources I'd like to use. Secondly, great question. The concept of foreign soldiers in the service of another nation is fascinating, and served the basis of my MA. In order to answer it, I would argue that the core reason for their romance is their longevity, continued existence, and achieving their zenith in comparatively modern conflicts. I would also argue they are not the first to enjoy such a reputation, and that the Irish Brigade in French service plotted a similar trajectory a century prior, and this answer should help contextualise the romantic image surrounding the legion.

Before tackling this, it may be wise to evaluate exactly what you mean by "romantic". Obviously the Foreign Legion has had an illustrious service in the late 19th and twentieth centuries in particular, and if we choose to equate a celebrated combat record to romance then yes, absolutely they are romantic. The idea of a band of vagabonds given one more chance, a clean slate, and the toughest missions the nation requires of them is the underdog story at its most primal. One only has to look at cinema to see countless examples of this kind of story; The Dirty Dozen, the Magnificent Seven, even Rogue One (if the mods pardon some sci-fi!) to name a few off the top of my head.

A distinction therefore needs to be drawn between the foreign nature of their soldiers, and the incredible challenges they overcame. Are they romantic due to their multicultural composition? Or rather are they celebrated due to their military record?

Let us consider the military angle first of all, and the origin of the Legion's celebrated status. The Legion's first 'famous' battle was the skirmish at Camerone in 1863. Here, a small detachment of legionaries held off a numerically superior force, and were allowed to walk away. Famously their commanding officer Captain Danjou was killed during the battle, and his wooden hand became a touchstone and relic of the legion thereafter. Every year the Legion celebrate Camerone, and with such a celebration one can see the origin of a staunch regimental tradition. This is a crucial factor when considering longevity. Old regiments with traditions associated with them are likely to catch the public's eye. They mark themselves out from the generic rank and file, and when this is actively encouraged both through their foreign composition and deployment, we can start to see how the Legion built its mythical status from the inside out.

How has this myth endured? Through selective memory of certain engagements. If one asks about French Foreign Legion service during the early 20th century, you'll probably have Bir Hakiem thrown in your face. Again, this battle in Libya saw the Legion mount a staunch defence against overwhelming odds. What about the latter portion of the 20th century? Well despite being a catastrophic defeat, Dien Bien Phu tells a similar story. The Legion, stranded in hostile conditions, fighting against the odds. You may have started to notice a pattern! (It is worth noting that the Legion's actions in Indo-China were largely despicable, and are a far cry from any sort of romance whatsoever. For a basic primer on this, try Max Hasting's Vietnam.)

So what we have is a group of 'underdog' soldiers, being put in situations which are almost impossible to overcome, and succeeding in doing so, all within recent memory. In addition, they are still in active service. This presence in the modern military has allowed their mythos to survive compared to other, arguably more romantic groups. For the sake of comparison, I would like to discuss the Irish Brigade of France in the 18th century, and hopefully explain how an equally celebrated foreign contingent both came to praise, and eventually faded away.

First of all, let us consider the soldiers themselves. Like the Legion, the odds were very much stacked against the men of the Irish Brigade. They were exiles, sent away from their homeland for supporting Catholic James II in a war against the new English regime of William of Orange in 1689-91. Their French hosts hardly viewed them with much enthusiasm upon their arrival. "Il est fort foible!" declared the Comte d'Avaux upon seeing them disembark. Overall, their inauspicious beginning mirrors the origin of the Legion in at least some aspects. Whilst they were more homogeneous, they weren't seen as pleasant company and there are many stories of Irish soldier turning to highway robbery on the roads around the exiled court of James II.

Like the Legion, this changed following several battles in which the Irish contribution became famous. Most of these early engagements took place during the War of the Spanish Succession. At the siege of Cremona (1702) Irish soldiers, roused from their beds and without uniform, held off a Holy Roman attack in brutal streetfighting. At the defeat at Blenheim (1704), the Irish again excelled, to the point that the Allied commander Colonel Goore (whose command had been devastated by the Irish attack) had nothing but praise to offer them.

This romantic status was triumphed in both Ireland and in France, and the musical tradition surrounding the brigade combined with their integration with French society both show how popular they were at the time. However, they would in due course slip into obscurity. As the century progressed, more and more French (or other nationalities) joined the ranks, and the Irish Brigades began to be less and less Irish. This loss of identity and regimental tradition which is so critical to the continuation of the Foreign Legion's mythos eventually saw the Irish Brigade disband. It was partially incorporated into other Regiments, and some went to serve the British crown instead.

What we can see here is a pattern of a disparate band, whose unique foreign-ness lends a certain quality worthy of extolling, and whose combat performance only enhances that uniqueness. I could offer other examples too; the Irish Brigade in the American Civil War, the Swiss Guard of France, the 442nd Combat Group in WW2. However what sets the Legion apart is its continued endurance and relevance in the modern day. The fact that it has continued to serve allows their mythos to continue as well. I hope this has answered your question, and I am an open door when it comes to follow-up questions as well.

Sources and further reading.

Hastings, Max, Vietnam

Hogan, James, (ed) Negociations de M. le Comte D'Avaux en Irlande

McGarry, Stephen Irish Brigades Abroad; From the Wild Geese to Napoleon

Murtagh, Harman., 'Irish soldiers abroad 1600-1800' in Bartlett & Jeffery (eds) A Military History of Ireland

Reynolds, Robert Grey, The Battle of Bir Hakeim: June 1942 Triumph of the Free French