It was a birthday party a century in the making, and it was double the fun.

Amy Pollock and Irene Stephens celebrated their 100th birthday on Tuesday in Cobden, about 115 kilometres west of Ottawa.

The identical twins are believed to be Ontario's oldest set of twins; possibly the oldest in all of Canada as well.

Dozens of relatives came to the Caressant Care home in Cobden for the celebration -- some flying from as far away as Australia and China.

"It's nice to see everybody," Amy Pollock said of the gathering.

The twins were born Amy and Irene Wallace on a farm in nearby Foresters Falls, on Queens Line Road. It was an uncertain beginning; they were born premature and weighed a combined five pounds.

Doctors advised their family to put them in a basket on a stove to keep them warm.

They spent their first 22 years in that home, which remains in the family today. After that, their paths diverged.

Amy settled down with Harry Pollock, a farmer, in Ingleside near Cornwall. Irene headed west, studying at UBC before becoming a public health nurse.

That was a time when women were forced to choose between having a career and a family, so she had kids later than her twin sister. Irene met Robert Stephens, and settled down in Vancouver.

Although they took different paths, the similiarities are striking. Both had four children; two boys and two girls. Both have stayed away from drinking alcohol. Both are avid gardeners. And they were both driving cars well into their 90s.

They also share a sense of humour, playing pranks on people to take advantage of their identical appearances.

"Lots of times, we got mixed up...I pretended I was her. We fooled a couple of people," Amy said on Monday.

Their kids share a memory of when the sisters were on their way back from a wedding, and decided to trade clothes on their train...then trade children.

When Irene's husband died in 1991, she soon moved back from Vancouver and settled in Cobden, much closer to her identical twin sister.

"I think they've both led very clean lives and very active lives," Doug Stephens, one of Irene's sons, said. "My mother was gardening until she was 93. My aunt worked and lived on a farm and worked hard all her life."

Amy remained involved in her church congregration well into her 90s, playing the organ for anyone who asked.

So what's their secret to longevity? The twins didn't provide one. But it might be in the mindset Amy expressed when asked how she felt at 100 years old.

"Am I 100 years old? Oh no ... it's just a number."