The acquisition by each company of half of the iconic Super Pit in late 2019 was the catalyst for one of the most logical deals of the past decade.

The ink was barely dry on each company's acquisition when people started talking about a potential merger between the two.

While the companies publicly maintained the focus was on bedding down the acquisitions and unlocking the potential of KCGM, the ‘will they, won't they?' talk got louder as 2020 rolled on.

Some put the speculation down to deal-hungry bankers, but by the time October rolled around, it was all anyone could talk about.

On October 6, Northern Star and Saracen formally announced a nil-premium scrip merger of equals that would see Saracen shareholders receive 0.3763 of a Northern Star share for each share held, as well as a special, fully franked dividend of A3.8c per share.

Then-Saracen managing director Raleigh Finlayson described the merger as "one of the most logical and strategic M&A transactions the mining industry has seen", while then-Northern Star executive chairman Bill Beament said "only this merger can deliver synergies of this value for either company - this is M&A that works".

The deal created a 1.6Moz per annum producer with a pathway to 2Mozpa by FY27 from three key production centres, Kalgoorlie, Yandal and Pogo in Alaska.

The merger also consolidated ownership of Kalgoorlie's iconic Golden Mile for the first time in its 125-year history.

"I suppose we've had a ‘try before you buy' here," Finlayson said.

"Clearly when we became joint venture partners, every day [a merger] became more and more logical."

Announced days out from Diggers & Dealers 2020, the merger was unsurprisingly the talk of the event.

Investors toured the Super Pit on the Sunday before Diggers and at a sundowner that night overlooking the pit, WA premier Mark McGowan endorsed the merger.

The market was almost unanimous in its approval of the deal, with both companies rising about 10% each on the day it was announced.

The deal created a new Australian gold major with the second-highest production and market capitalisation behind Newcrest Mining.

While the merger wasn't finalised until February 2021, work on the integration began from the day it was announced, and the company has reported a smooth transition.

The completion of the deal saw the enlarged Northern Star admitted to the ASX 50.

Beament left Northern Star earlier this month, with highly respected Wesfarmers chairman Michael Chaney joining the company as non-executive chairman.

Finlayson is MD, but Northern Star CEO Stuart Tonkin is expected to transition to the top job in the coming months.

When the deal was announced, the pair forecast it to unlock $1.5-2 billion in pre-tax synergies.

Those synergies should become much clearer later this week when Northern Star holds its annual strategy day - the first since the merger.

The investor event is expected to be a major catalyst for the company with more details on milling synergies in the Kalgoorlie region expected.

"It's going to give good clarity about what our assets will look like in five years," Beament said shortly before his departure.

"It will be a better portfolio than Agnico Eagle, in my view."

Northern Star currently has a market cap of $12 billion but its shares have underperformed its peers.

BMO Capital Markets analyst Brian Quast recently said the decline was overdone as he lifted his recommendation to outperform with a $16 price target.

"Northern Star has a rare combination of size and organic production growth, in exclusively tier one jurisdictions," he said.

"Trading at a discount to peers and with an approaching investor day, we like the near- to mid-term setup for Northern Star."

The merger of Northern Star Resources and Saracen Mineral Holdings is a nominee for Deal and/or Merger of the Year in the 2021 MNN Awards.