The Port Arthur massacre in 1996 remains one of the worst mass shootings in Australia’s recent history.

No one in Tasmania could have predicted a lone gunman would open fire and murder 35 people on a vicious killing spree, forever changing their seaside town.

The tragedy sent shockwaves around the nation, and Australians needed a leader to assure them the senseless act would never happen again.

Twelve days later, that’s exactly what happened.

Then prime minister John Howard was only six weeks into the job when he announced the most comprehensive crackdown on gun ownership in modern Australian history.

Devastated by the killings, he capitalised on the nation’s horror to persuade all the states and territories to agree to uniform gun laws.

The Port Arthur massacre devastated dozens of families. Photo: Getty

Under his leadership, all states and territories agreed to tighten the rules around who can own and use self-loading rifles and shotguns, and introduced a ban on automatic and semi-automatic firearms.

The government also brought in a national firearm registration system, as well as a mandatory “buy back” scheme, where gun owners were compensated for handing in any prohibited and unregistered weapons.

But it didn’t come easy.

The gun lobby ran a ferocious campaign against the gun laws, and there was deep anger in rural and regional Australia about the changes, especially in Queensland.

Mr Howard stayed strong, and on May 10, 1996 the new rules were adopted across Australia.

It was arguably his finest moment as prime minister.

Decades later, his swift reaction is still praised – even by his enemies on the left – and is cited as an example of leadership by gun control advocates in the US and around the world.