MELBOURNE, Australia — Those who celebrate Australia Day, the country’s national holiday, associate it with barbecues and pool parties. But for those who protest against it, it is a reminder of the continent’s brutal colonization.

On Tuesday, tens of thousands of people marched through Australia’s major cities in opposition to the holiday, which they instead refer to as Invasion Day. It is a blunt reframing of the legacy of the arrival of the British 233 years ago, which set in motion centuries of oppression of Indigenous people.

Year upon year, these protests have grown and gained political traction, and Tuesday’s were bolstered by the global Black Lives Matter movement. Here is a look at this contentious day.

he remarked that it would serve only to “remind them that we have robbed them.”