NZ First made the final decision in a drawn-out process to join forces with Labour over National, one-year-ago today.
"In our negotiations both National and Labour were presented with that opportunity, working together, cooperating together for New Zealand," NZ First leader told media, last year.
"That's why in the end we chose a coalition government of NZ first with the Labour Party."
Today, now-Prime Minister Ardern's partner Clarke Gayford posted photos of the moment Mr Peters announced he would go with Labour.
"We watched on TV like everyone else, except I pointed a camera the other way," he wrote.
"What an incredible year it has been, what a year ahead. Welcome to the ride."