Yet when Seifeddine Rezgui's martyrdom came it was not on the battle grounds, but rather unleashed on unsuspecting tourists lying on sunbeds on a Tunisian beach. Photo / @RamiAILolah
The photograph is like countless others released by the Islamic State's propaganda wing - a young man sits flanked by a pair of Kalashnikovs, grinning excitedly at the prospect of proving himself in combat.
Yet when Seifeddine Rezgui's turn for martyrdom came, it was not in the tough battlegrounds of Syria or Iraq, but in a killing field that could scarcely be easier - a group of unsuspecting tourists lying on sunbeds on a Tunisian beach, some of whom may not even have seen his face.
Nonetheless, by dint of sheer bloodthirstiness alone, his act of "lone wolf" savagery has guaranteed him a place in history, as the perpetrator of the worst single act of terrorism against British citizens since the July 7 bombings in 2005. So who exactly was he?
Alarmingly for the Tunisian authorities, the most obvious answer to that question is that far from being the exalted "Soldier of the Caliphate" that Isil has hailed him as, he was just an all too typical Tunisian youth.
According to Tunisia's Prime Minister, Habib Essid, Rezgui was a 23-year-old engineering student who originally hailed from Gaafour, a drab and unremarkable town some 50 miles south-west of Tunis.
He had never travelled abroad, Mr Essid said, and was not known by the police to hold extremist views.
"We were all shocked when we heard the news and saw his picture, and his mother was devastated," added his uncle, Ali Al-Rezgui, speaking to The Telegraph outside the family's small, whitewashed home in Gaafour on Saturday.
"Yes, he went to mosque and prayed, but just like the other young men, he would then go to a cafe and play football with his friends.
I last saw him on Thursday, he said 'hello', and then he left that night and went to his friend's house. We didn't know where he was going, and there were no goodbye's.
The entire family is shocked at the hidden reality of what he was capable of."
Yet like most Arab youngsters these days, Rezgui appears to have been a keen user of social media.
And a Facebook page believed to belong to him paints a very different picture of his outlook on life. For amid the fan postings about rap music, Real Madrid and the Tunisia's chances in the Africa Cup, there are numerous postings in support of Isil, as well as several of their propaganda videos.
Notably, most of his radical postings appear to have started only early last year, prior to which he seemed to be more interested in rap music and sharing jokes.
His final entry is New Year 2015, and read: "May God take me out of this unjust world and perish its people and make them suffer. They just remember you when they die."
Why Rezgui stopped all his Facebook activity after that date will now be a matter for the authorities, who on Saturday seized a laptop during a raid on his family home in Gaafour, during which his parents were reportedly arrested.
But if he was being groomed to carry out an attack, whoever was his handler might have advised him to stop all online activity well before his planned assault.
That same handler might have also had advance knowledge of March's planned atrocity at Tunisia's Bardo Museum, in which 19 people died, and have been anxious that Rezgui did nothing to draw attention to himself in the aftermath.
Quite who those "handlers" were - if indeed he had any - remains unknown as of yet. But a possible clue may lie in Rezgui's Isil nom de guerre, Abu Yahya al Qayrawani.
The last name is a reference to the Tunisian city of Kairouan, where Rezgui last year enrolled in a master's degree at the local university.
The ancient city, which sits on the edge of the Sahara desert, was one of the earliest centres of Sunni Muslim Islamic scholarship, and has long been considered one of holiest sites in the Muslim world.
More recently, though, it has also been a centre for Islamic radicalism, and until two years ago was the main gathering place in Tunisia for Ansar al-Sharia, the radical Islamic group that first sprung up in neighbouring Libya after the 2011 Arab Spring.
Following Ansar al-Sharia's attack on a US embassy compound in Libya in 2012, in which the consulate, Chris Stevens was killed, it was declared a terrorist group by Washington.
At the time, the Tunisian government chose not to follow suit, wary of being seen to act in the same authoritarian fashion as the country's deposed dictator, Zine El Abidine Ben Ali.
But in 2013, it too outlawed the group, after a riot erupted when Tunisian police stopped its followers holding their annual rally in Kairouan.
Since then, many of its hard core members are believed to fled abroad to fight with Isil in Syria and Iraq.
Indeed, such is the exodus that Tunisia is now believed to have contributed some 3,000 jihadist fighters to the conflict, more than any other country.
The irony is that as a Facebook-surfing 20-something, Rezgui was also part of the exact same generation of young Tunisians who kicked off the Arab world's biggest ever steps towards democracy.
In Junuary 2011, Facebook-orchestrated street protests overthrew President Ben Ali, following outrage over the death of a fruit vendor, Mohamed Bouazizi, who set himself on fire in despair at harassment by local officials over his lack of a trade permit.
That then sparked off copycat Arab Spring revolutions in Egypt, Libya, Syria and Yemen, all of which hailed tiny Tunisia as their inspiration.
Yet as it turned out, Tunis's web-savvy middle classes were not the only ones who saw Mr Ben Ali's fall as a chance for change.
So too did Islamist parties of various hues of radicalism, whose religious agenda has earned them strong support and sometimes near-block votes in Tunisia's more conservative rural interior.
Both secularists and Islamists now have their share of power in parliament, and in contrast to other Arab Spring nations, so far the country's efforts at democracy have been largely successful.
All the same, secular politicians have been assassinated and harrassed, and while radical religious parties have been subjected to periodic bans and crackdowns, they continue to pose a threat.
Meanwhile, with post-Arab Spring Tunisia still suffering from painfully high unemployment, the same sense of despair that drove Mohamed Bouazazi to self-immolation is motivating plenty of other young Tunisian men to give up their lives for jihad.
Was that the case with Rezgui? His uncle said that the family had been traumatised in 2010 when Rezgui's younger brother had died in a lightning strike.
But otherwise, he insisted, there had been no sign of anything to worry about.
"He used to use hair gel and wear the nicest of clothes, and he used to break dancing," he said.
"He even used to go to competitions and things like that in Tunis, he was well known for that here. He didn't even have a beard, and I've never seen him with anyone with a beard. We have extremists like that in Gaafour, but never have I seen him with them.
Now he's shooting people with a Kalashnikov, it's just so confusing."
Whether his parents were similarly in the dark is now a matter for the authorities, who on Saturday were still questioning his mother and father up in the capital, Tunis.
However, had his parents, his uncle or indeed the police ever browsed the main page of what appears to be Rezgui's Facebook account, one particular posting might have given them a very clear inkling.
"If jihad is a crime," he wrote, "the world shall know that I'm a criminal." On Friday, with his massacre of innocent civilians on the beach, he proved that to the world beyond all doubt.