Sitting in an abyss of grief after losing his family in the Port Arthur massacre, a father's courage and strength to call for change has been hailed as a defining moment in Australian history.
"As the person who lost his wife and two beautiful daughters at Port Arthur, I am writing to you to give you the strength to ensure no person in Australia ever has to suffer such a loss," Walter Mikac wrote to then prime minister John Howard.
That was nine days after the country's worst mass shooting when a gunman killed 35 people in the Tasmanian historic site on April 28, 1996.
Among the victims were Mr Mikac's wife and their two young daughters.
Mr Howard responded by saying that in the 22 years he had been in politics, he had not experienced any other event that so shocked the community and galvanised the political leadership.
"I believe that out of this nightmare, there have come positive changes for us as a nation," he told Mr Mikac.
As the nation's leaders grappled with the tragedy in following weeks, Mr Mikac again wrote to the prime minister and police ministers ahead of a meeting that led to historic gun laws.
"As I sit at my home with tears running down my face still reading cards for (wife) Nanette, (daughters) Alannah and Madeline, I find it hard to believe ... the reform package ... could be reneged upon," he wrote.
"Be strong and act now."
The correspondence spurred national gun control legislation that passed parliament with bipartisan support.
Mr Howard confirmed the grieving father's words stayed with him throughout.
"The depth of your own personal tragedy is a powerful symbol to those of us exercising political leadership," he wrote back.
More than 25 years later, the National Museum of Australia will acquire the series of letters between the grieving father and the nation's leader.
Feelings of powerlessness and deep grief compelled Mr Mikac to call for action.
"I remember at the time, all I wanted to do was shut the curtains and not have anything to do with the world," he told AAP on Thursday.
"But I thought that's not going to change anything.
"They're not going to come back."
Prime Minister Anthony Albanese described Mr Mikac's words as "one of the most extraordinary things I have ever read in my life".
"Mr Mikac, your words belong to history now," he said in a speech to over 100 guests of an event at Parliament House marking the occasion.
Guests became emotional as the prime minister described Mr Mikac as a hero.
"When your children are aged three or six, you are their hero - not necessarily for anything you do, simply for who you are," Mr Albanese said.
"Tragically, Alannah and Madeline didn't live long enough to know that their dad is a hero to all of us."
Opposition Leader Peter Dutton, who stepped in for Mr Howard due to illness, spoke of the words that "dripped emotion" and defined Mr Howard's legacy in office.
"In perpetuity, these letters will stand as testament to your bravery, your love as a husband and as a father," he said.
Mr Mikac received a 30-second standing ovation in the House of Representatives after the prime minister acknowledged him.
"You have made a difference to this country. We pay tribute to you today and we honour you today," Mr Albanese said during Question Time.
State and territory police ministers last week agreed to consider a model for a national firearms register to help police tackle gun violence which will be put to national cabinet in July.
