The sport, invented by the founder of the modern Games, Baron Pierre de Coubertin, celebrates its Olympic centenary in London having made its debut at Stockholm 1912.
It has been under pressure to modernise, and since 1996 the fencing, swimming, jumping, running and shooting have all taken place on the same day, having originally been staged over four or five days.
That was the format for the last Olympic Games at Beijing 2008, but in 2009 the sport changed fundamentally with the introduction of the combined event.
The running and shooting elements were put together into a biathlon-style event, which now provides an exciting and unpredictable finale.
Last year, the decision was made to change from air pistols to laser guns, making the sport more accessible and safer for children.
It has been a challenge for the athletes to adapt but Dr Klaus Schormann, the President of international governing body the Union International de Pentathlon Moderne (UIPM), said the best will still come out on top.
Schormann said: 'What is very good is these athletes that are sitting here and also other athletes performing at the Olympic Games, they won in the past and they're winning again.'
Reigning women's champion Lena Schoneborn of Germany will go into Sunday's women's competition as one of the favourites, having added numerous World Cup wins to her Beijing 2008 gold, as well as the European Championships and World Cup Final titles last year.
The 26-year-old has high hopes, although she insisted her Beijing 2008 title is irrelevant to her London 2012 chances, saying: 'Quite a lot has happened in the last four years.
'I took the combined event as a new challenge, so for me this is a completely new competition. So far I don't have the title of 2008 in my mind. It's everything back to zero.
I don't have the title of 2008 in my mind. It's everything back to zero.Lena Schoneborn
'I try to focus on the way and not the destination. Of course, I have high expectations on myself because everything's been going well and I want to stay at that level.'
Lithuania's combined event specialist Laura Asadauskaite goes into the Games ranked number one ahead of world champion Mhairi Spence from Great Britain.
Other names who are expected to challenge include France's three-time world champion Amelie Caze and 2011 world champion Viktoriya Tereshchuk of the Ukraine.
The men's sport is dominated by Russia, who are represented in London by world champion and top-ranked Aleksander Lesun and Andrei Moiseev, who is bidding for an unprecedented third consecutive Olympic gold medal.
With two athletes from each country allowed to compete, Russia had to leave Ilia Frolov and Serguei Karyakin, who are ranked third and fifth in the world, behind. The Russian quartet are joined in the world's top five at number four by Hungary's former world champion Adam Marosi.
Seventh-ranked Ricardo De Luca put himself in contention with victory at the European Championships in July, while the 26-year-old holds the world record for the combined event at 9:41 for 15 successful shots and 3000m of running.
De Luca said: 'I don't think about the other athletes. I think about myself, my training and my possibilities. On Saturday I know that, if I perform at my maximum ability, I have the chance to do something good.'