At first glance they may seem to be just portraits, trinkets or postcards. But they are also evidence that at some point, two people were connected by love.

When National Museum of Australia curator Jono Lineen thinks about Australia's "golden boy of boxing" Les Darcy and Winnie O'Sullivan's love story, he gets goosebumps.

One of the best representations of the young couple's heartbreaking love story - in the museum's collection, at least - is a small mourning locket that holds Darcy's photo and a lock of his hair.

When the couple met, Darcy was already a big name in boxing, splitting his time between the Hunter Valley and Sydney's Lord Dudley Hotel. It was at the hotel that he met the love of his life, O'Sullivan.

"We're talking about 1915, so it wasn't the type of romance that we might think about today," Lineen says.

"They would probably not have been together alone without a chaperone. But they spent a lot of time walking together with friends. They were sweethearts."

But while Darcy was king in the ring, it was a different opponent that saw Australia's golden boy fall from grace.

"The situation in Australia started to change with World War I. Prime Minister Billy Hughes wanted to institute conscription," Lineen says.

"Les was a young, strong guy. He was probably the most popular sportsperson in Australia. But he refused to sign up."

This was mainly due to his mother. Darcy had twice brought home the paperwork for his mother to sign - a requirement for men under 21 - and twice his mother threw the paperwork into the fire.

"There was pressure on him definitely from the government, and from parts of society. In fact, Les was sent white feathers in the mail, which was considered the biggest insult during WWI," Lineen says.

Instead, Darcy decided to make his way to the United States. The plan was to earn a life-changing amount of money by winning a few fights and then join the WWI efforts from there. However, he was denied a passport, and was forced to stow away in a cargo ship travelling to the US. He ended up in Memphis, Tennessee, but before he could fight, Darcy fell ill.

The fighter had lost his two front teeth during a fight in Australia, which were then reattached with gold pins. They became infected and, in a time before antibiotics, the infection spread.

Meanwhile, O'Sullivan was already on her way to the United States to be with her sweetheart. When she arrived on May 24, 1917, she only had a couple hours with her sweetheart, before he died aged 21.

"Legend has it that she took a lock of hair on his deathbed, and put that in the locket, and kept it with her until the day she died," Lineen says.

"When you look at the locket, what you see is that one side of it, the engraving on it, it's quite shallow. The metal is bent, and it's possible that she kept it in her pocket, and would rub it. She could never let Les go."

Without knowing anything about the National Portrait Gallery's painting of Lola Montez, it would be easy to dismiss it as a depiction of an 1800s noblewoman.

In reality, the portrait is the embodiment of King Ludwig I of Bavaria's obsession with his mistress, and in a way, Montez's love of her own freedom.

"It's the standard now for women to seek opportunity and nine times out of 10, getting it," gallery curator Joanna Gilmour says.

"The fascinating thing about Lola is that she chose to do that and to a degree, really succeeded in a time when others could not. You just can't imagine how brave it must have been for her to do that, given everything that was against her. She was not someone from a particularly distinguished background. She's this fantastic example of a self-made woman."

Born in Ireland as Eliza Gilbert, Montez lived many lives before even reaching Bavaria. At the age of 14, her mother tried to marry her off to a 60-year-old. Instead, Montez chose to run off to marry Thomas James. All was well until he was unfaithful and the pair separated. It was then that Montez refused the spinster life, taking on her new name and the persona of a Spanish dancer to earn her keep.

Montez travelled Europe performing, which eventually brought her to Munich. There the dancer attracted the attention of King Ludwig, and he just had to have her.

"King Ludwig was so enamoured of her that he had a number of portraits made of her including a very famous portrait that is now in the Gallery of Beauties at Nymphenburg Palace," Gilmour says.

"The story goes that he not only had that painting made ... but also another painting that he gave to Lola. There's a theory that the painting we have is the painting that Lola had herself."

While King Ludwig was obsessed with her, others were not. In 1847, Montez convinced the king to turn her into a countess, despite the fact she was not a Bavarian citizen. It was one example of how much influence she had over King Ludwig, and it caused protests and saw the entirety of the king's cabinet resign. By March, 1848, the voices of possible revolution were growing loud and the king abdicated in favour of his son.

Montez fled the country, expecting Ludwig to come to her rescue, but he never did.

All of this was before she even thought about travelling to America or Australia to perform - which is how many Australians know her.

It was in Australia that her signature Spider Dace came about. It saw her enacting having a spider caught in "an extremely short gauze skirt", causing outrage in some places - her appearance in Melbourne being met with calls for her arrest. Goldfield towns such as Bendigo, Ballarat and Castlemaine, however, couldn't get enough of Montez.

Everyone wants their wedding day to be special but one Australian couple took it to a whole new level.

On July 30, 1932, John and Gladys Cousemacker made history as the first Australian couple to marry in the sky. What's more, it was one of the few 1930s weddings to be recording on cinema-quality film, and is now in the National Film and Sound Archive.

The wedding was won as part of a competition organised by Sydney's Regent Theatre as a promotion of the Paramount romance film Sky Bride.

"You'll find that a lot of cinemas engaged in gimmicks to try and encourage patrons to come and see films," archive curator Jeffrey Ray says.

"Sometimes it was having a screening of Rin Tin Tin where you bring in your dog. Often you'd have celebrities from movies turning up and you can meet them. This is just another spectacle to get patrons interested in a film."

The couple took to the air in a New England Airways Avro 618 Ten - a plane only capable of carrying two crew and eight passengers. In the case of the sky wedding, the seats were filled with their fathers, two camera operators, a radio announcer and a journalist, as well as Reverend H. Mills.

At the time Ms Cousemacker was questioned about the religious aspect of such a novel ceremony. She replied: "I see no reason why a wedding in the sky cannot be carried out with the same spiritual reverence and beauty as that performed in a private home, or even a church".

The rest of the couple's guests - as well as those who were captivated by the idea - were crowded on the ground, listening to the exchange of vows through a short-wave radio transmitter. It was then re-broadcast by 2UW radio.

The plane landed and the couple was greeted by cheers and confetti before they went on to a reception in a Mascot Airport hanger.

Wartime love stories always have a tinge of sadness to them. As such, so do the tokens of affection collected during this time.

In the National Library of Australia's collection - and for that matter, in the Australian War Memorial's collection, as well - there are embroidered postcards that read: "A Kiss From France".

It's no surprise that both institutions have similar postcards. An estimated 10 million handmade cards were produced during WWI, with the embroidery largely carried out by women in France and Belgium, as well as by Belgian refugees in the United Kingdom.

One such postcard in the library's collection includes a message on the reverse.

"Just a postcard to tell you that I am like Johnie [sic] Walker, still going strong. This is about the only way I knew of sending you a kiss from France. You won't think me too rude, will you? I have not had a letter from you for some time. I always look forward to getting a letter from you. They are ... always cheerful."

The library has no further information about what happened to the couple, or indeed if the sender was able to kiss his beloved in person once more.

Other artefacts in the collection, however, are less mysterious, including the wedding photo of Kate McLeod and George Searle. The photo is an example of the many studio shots taken of newlyweds during WWI.

By using the photo's inscription, "With love from Kate and George 17/11/15", curators were able to learn more about the couple.

Albert George Searle and Kate McLeod married in November 1915 - a few months after Searle enlisted and just days before he left for Egypt. After serving in Egypt he was invalided out of the army in 1916.

Searle isn't someone who would necessarily appear in the spotlight for his war efforts. His military record is not that of a traditional "hero". He wasn't in any key battles, and he didn't return home with medals. But he is an example of the more than 400,000 volunteers who served their country. And the couple's wedding photo depicts the same look of uncertainty as many others did. This uncertainty was not just in regards to the war itself but also the challenges faced upon Searle's return.