Many years ago, four Gryffindor boys formed a strong bond of friendship. Little did they know the impact this would have on the wizarding world.
Prongs, Padfoot, Moony and Wormtail in their transfigured animal forms.

‘I solemnly swear that I am up to no good.’

‘My whole family have been in Slytherin,’ he said.
‘Blimey,’ said James, ‘and I thought you seemed all right!’
Sirius grinned.
‘Maybe I’ll break the tradition. Where are you heading, if you’ve got the choice?’
James lifted an invisible sword.
‘“Gryffindor, where dwell the brave at heart!” Like my dad.’
Harry Potter and the Deathly Hallows

James Potter first met Sirius Black aboard the Hogwarts Express. They sat in the same carriage as Lily Evans and Severus Snape, and let’s just say they didn’t exactly hit it off with Snape. After the Sorting, James and Sirius took a shine to the quiet but clever Remus Lupin, who had taken pity on a short, slow boy named Peter Pettigrew. From then on, they were inseparable.

The four were viewed (by themselves at least) as the rock stars of Hogwarts. James was a Quidditch hero and, in case anyone forgot this detail, frequently messed up his hair for added windswept effect and tossed around a Golden Snitch. Sirius was a good-looking rebel and proudly defiant of his family’s Slytherin affiliations, adorning his bedroom walls with Gryffindor colours along with pictures of motorbikes and Muggle girls. Quick-witted Remus was the brains of the operation who tried (and often failed) to keep the rest of the group in check. As for Peter, well... Peter was there too. His habit of attaching himself to strong personalities would play an important part in later events.

Moony Padfoot Prongs and Wormtail at Hogwarts by the lake

But the gang were not universally adored. They were particularly cruel to Severus, who would never forget how horribly he’d been treated even into adulthood. Lily too was no fan of James, whom she described as ‘an arrogant toerag’. Like most teenagers, the boys had a lot of growing up to do.

‘Sometimes you remind me a lot of James. He called it my “furry little problem” in company. Many people were under the impression that I owned a badly behaved rabbit.’
Harry Potter and the Half-Blood Prince

Tragically Remus carried an affliction, which his parents, Hope and Lyall Lupin, thought would prevent him from attending school (of course, Dumbledore made special arrangements). As a child, Remus survived an attack which left him a fully-fledged werewolf. With his monthly transformations and ill health, he feared it was only a matter of time before his friends learned his secret.

‘And they didn’t desert me at all. Instead they did something for me that would make my transformations not only bearable, but the best times of my life. They became Animagi.’
Harry Potter and the Prisoner of Azkaban

Thus the Marauders were born. James became Prongs the stag, Sirius was Padfoot the dog and Peter, with more than a little help from his friends, transformed into Wormtail the rat. Remus also earned the nickname ‘Moony’ on account of his lycanthropy. Together they roamed the grounds as animals, exploring every nook and cranny of Hogwarts. Their greatest invention, the Marauder’s Map, recorded all their favourite secret passages and blazed the trail for future troublemakers.

The Marauder's Map

‘The Dark Lord’s servant’ – Wormtail’s betrayal

After graduating, the four friends were recruited into Dumbledore’s Order of the Phoenix. Mrs Potter (yes, James eventually grew on Lily) was also a member and soon the happy couple were celebrating the birth of their son, Harry. Sirius, who had been the best man at their wedding, was named the baby’s godfather.

However, all was not well. Once a certain prophecy came to light, little Harry was targeted by Lord Voldemort. The Potters went into hiding at Godric’s Hollow and, taking the advice of Sirius, appointed the unassuming Peter as their secret-keeper. Unfortunately, Peter had turned spy for ‘the biggest bully in the playground’ and saw a golden opportunity to win Voldemort’s favour. Thanks to his betrayal, James and Lily were murdered trying to protect their son.

Peter Pettigrew transforms back into a rat and escapes.

‘… it must have been the finest moment of your miserable life, telling Voldemort you could hand him the Potters.’
Harry Potter and the Prisoner of Azkaban

An enraged Sirius immediately sought revenge. During their confrontation, Peter caused an explosion that killed several bystanders before escaping into the sewers in his rat form, leaving behind his severed finger. Sirius, a member of the notorious Black family, was found at the scene of the crime maniacally laughing. He could hardly have looked more like a deranged murderer if he tried.

Sirius spent the next 12 years in Azkaban. Remus was heartbroken at the loss of his friends and found himself alone once more. Peter, who was posthumously awarded the Order of Merlin, laid low as a rat and was taken in by the Weasley family as a pet.

Pottermore illustration Sirius Black

‘Cat, rat and dog’ – an unexpected reunion

Shocking truths were revealed and important events were set in motion one night at the Shrieking Shack. Sirius had escaped Azkaban after spotting ‘Scabbers’ in the Daily Prophet. Meanwhile Remus had been made Professor Lupin and was teaching Defence Against the Dark Arts to James’s teenage son. Peter realised his number was up at Hogwarts with one old friend resident as a teacher, another an escaped convict and a suspicious ginger moggy on his tail. Once again, he faked his own death… and he almost got away with it.

Harry’s friends, the Marauders and even Severus Snape all wound up at the Shrieking Shack where the truth finally emerged. James’s presence was also felt in the form of his son’s Patronus. In Dumbledore’s words the following day, ‘Prongs rode again last night.’

Harry's stag patronus charges across the lake towards the Dementors.

Unfortunately, this took place during a full moon. Before Sirius’s name could be cleared Remus transformed and Peter escaped in the ensuing chaos. Afterwards Peter returned to his master, Remus resigned and Sirius went on the run with a fellow fugitive – a Hippogriff named Buckbeak. He always did like to travel in style.

‘I open at the close’ – the final gathering

Sirius died two years later, battling Death Eaters at his beloved godson’s side. Peter was strangled to death by his silver hand – a gift from Lord Voldemort – the moment he showed mercy to Harry. Remus, the last Marauder standing, was killed at the Battle of Hogwarts along with his wife Nymphadora Tonks. The couple left a son, Teddy Remus Lupin, to whom Harry had agreed to be godfather.

Tonk and Lupin standing together from the Half Blood Prince

We last saw the Marauders together (minus Peter, but joined by Lily) in the Forbidden Forest. Reunited by the Resurrection Stone, the Marauders helped Harry find the courage he needed to make the ultimate sacrifice. Thanks to this, Voldemort was defeated and peace was restored to the magical world. The Marauders were gone but their legacy would live forever.

Mischief managed.

‘You’ll stay with me?’
‘Until the very end,’ said James.
‘They won’t be able to see you?’ asked Harry.
‘We are part of you,’ said Sirius. ‘Invisible to anyone else.’
Harry Potter and the Deathly Hallows

Harry, accompanied by the spirits of his dead family and friends, approaches Lord Voldemort prepared to die.
Harry Potter to Fantastic Beasts