If you need reminding of Billy Vunipola's close links to Wales, just listen to the strong Gwent accent of his brother and England team-mate, Mako.

Then have a look at the old photo of a nine-year-old Billy sitting at a table, a boy of precocious heft towering over his fellow East Wales Schools Under-11s players, including future Wales wing Harry Robinson.

And for good measure, note that the Saracens number eight has known Wales and British and Irish Lions back-row Taulupe Faletau so long that the two regard each other as family, albeit unofficially.

Vunipola was born in Australia to Tongan parents and moved to Wales aged five when his father, Fe'ao Vunipola, signed for Pontypool in 1998.

A year earlier, Kuli Faletau joined another Gwent club, Ebbw Vale, and moved his family - including then six-year-old son Taulupe - with him to south Wales.

"A lot of the Tongan community kind of started their roots in Wales," Vunipola tells the BBC Scrum V podcast.

"When my dad came over a few in the community met up and made sure they compared notes on things like when they go shopping, all these little things Tongans didn't get when they came from Tonga.

"It was a support system and growing up we would visit them [the Faletaus] and they would visit us.

"I remember it was pretty bleak just in terms of the weather. It was the coldest thing I had ever experienced coming over from Tonga and Australia.

"People were very welcoming, especially when they knew you were good at rugby."

That much was clear about the Vunipola brothers from an early age.

"We were in Caerleon, so our first club was Newport High School Old Boys," Billy recalls.

"I remember playing touch rugby. I think I only played touch maybe three or four games. I would just stand in the middle of the pitch and watch all the little, fast kids run around me. I didn't really get the concept of it.

"And then a few weeks later they moved me up to my brother's age group and that's when I started to get my head down and getting into it, because there was contact and something I could contribute to the team, rather than just catching the ball and someone just ripping my tag off my hips.

"So that became more fun for me and probably less fun for people around me.

"After that, we just joined a club wherever we were so when we went to Pontypool we went to New Panteg, then Pontypool district and then East Wales and played against the likes of Sanj [Wales and Lions full-back Liam Williams] and all those boys coming through.

"We didn't really realise at the time that we would get all the way to the top, but it's actually it's a fun story and a fun memory to look back at, the teamsheets and the kind of players we played against without realising where they are now in the game."

Vunipola later moved from Pontypool to Bristol, where his brother, Mako - two years older - started his professional career.

Mako joined Saracens in 2011 and, although Billy signed for Wasps that year, he followed his big brother to the five-time English champions in 2013.

After nine years of playing in London and his schooling at Harrow, Billy's accent could be described as southern English with just a hint of his Tongan and Australian upbringing.

Mako, by contrast, has retained the unmistakable tones of south-east Wales - so why such a striking difference between the two?

"I don't know," Billy laughs.

"When I left to go to school at Harrow, or when we went to Bristol, he signed a contract to live with two Welsh boys for two years and he's kind of never left it.

"When he went to Millfield he was really close friends with lots of Welsh boys, Rhys Ruddock [born in Wales but now an Ireland international] being one of them and he and Toby [Faletau] are pretty close as well."

Billy and Mako have been Saracens team-mates since 2013 and they are also international colleagues, with Billy earning 51 caps for England and Mako 59.

The brothers and the rest of their family remain close with Faletau so, when it comes to playing against a Wales side including a man they affectionately refer to as their cousin, they still find it a wrench.

"We always make sure there is never any malice behind what we are doing to each other," Billy says.

"Sometimes you might want to go against someone in the opposing team but, with Toby if he is running at me, I will tackle him, but will never get up and push him in the head or anything.

"There's a relationship to keep there. He is funny and tough now having broken his arm. It's been a rough ride for him and hopefully we can both come out the other side of it."

'Lions 2021 is my next big goal'

Billy has also had his share of bad luck with injuries, with a shoulder problem forcing him to withdraw from the Lions' squad for their 2017 tour of New Zealand.

Mako and Faletau both started all three Tests of the drawn series against the All Blacks, having also played on the Lions' victorious tour of Australia in 2013.

Missing out on that family affair remains a source of anguish for Billy.

"I was happy for my brother and Toby to be starting, but I also had a bad feeling of envy, knowing I could have had a chance to be with the team," he says.

"I took myself out of it - I went to New Zealand, stopped off in Tonga and saw my family. I thought I wouldn't have that same feeling again but my family were so engrossed in it - they had red tinsel everywhere, like it was Christmas! Everywhere I went, you couldn't get away from it.

"That feeling still sits with me but, at the same time, the decision was with me to pull out of the tour.

"I felt it would have been selfish to go on a tour and not give my best, where I wouldn't have been at my best. I felt that would have been unfair to the group."

The pain remains, but it is also a source of inspiration.

With Billy still only 27 years old and Mako and Faletau both 29, all three will be in contention for the Lions' tour of South Africa in 2021.

And Billy will be more determined than ever to be there, to make up for lost time.

"That's my next big goal," he says.

"The last few times I played for England I feel like I haven't played at my best. It coincided with me coming back from injury, trying to get back to fitness.

"It's important to play well for England and to go on tour against the world champions South Africa would be incredible."