Charteris hails from Llandeilo and was educated at Ysgol Gyfun Tre-Gib in Carmarthenshire, but he was born in Camborne, Cornwall, and also spent three years at university in Bath, studying a sports science degree.
He lived in Bath for a total of eight years as he commuted back and forth to Wales during the early part of his rugby career, he is still in touch with many of his peers there, but he has only faced England once in his 23-cap career to date so has had little opportunity to gauge allegiances.
The 11-times capped Lydiate, who like Charteris would face England for only the second time at senior level, is testing loyalties closer to home, with his dad, John, hailing originally from Salford and particularly proud of his heritage when it comes to some sporting rivalries.
But both players are more than confident the relevant Englishmen in their brethren will be in their corners for the pre-Rugby World Cup warm-up at English HQ and for the return leg of the double-header at the Millennium Stadium a week later.
"Blood is certainly thicker than water when it comes to the rugby for my dad, there is never any question of split loyalties when he watches me play or when he watched my brother, Jack, for that matter," said Lydiate, who has started in the back row in all but one (he missed the South Africa clash in the 2010 Invesco Perpetual Series in November) of Wales' 10 internationals so far this season.
"We were both born and bred in Wales and, actually, my dad didn't really get into rugby union until the two of us starting playing it, so it's probably been quite easy for him.
"He was a football fan in his youth and supports Manchester United and, coming from Salford, the rugby he watched was rugby league.
"I don't know what he does at anthem time when he is watching me, but I know he sings the Welsh one when we are together and I imagine if I'm playing in either of the games this summer he'll sing them both.
"But it's probably the same for dads the world over, if your son is playing you support them, so there is no dilemma there for him at all really."
Charteris must go to further lengths to ensure he gets support from his old English student mates, but he is equally confident he has all the angles covered.
"I've told them, if I make the squad, not tobother coming to watch me unless they are wearing Welsh gear, so there won't be an English rose in sight," said Charteris.
"I've dished out a lot of my old kit, just to make sure there aren't any excuses, although it doesn't exactly fit them all that well.
"It's a case of once a student always a student, making them very susceptible to bribery, but they are all genuinely supportive of me."
The 6 foot 9 inch lock Charteris is back to full fitness and in top form for the Dragons after an injury lay-off with an elbow problem limited his game time at international level this season.
He has had to watch from the stands as Wales regulars Bradley Davies and Alun Wyn Jones have formed a formidable partnership in the second row, but he is not giving up on a starting place easily and made his comeback against the Barbarians in June.
"Bradley (Davies) and Alun (Wyn Jones) have been going well, but all I can do is work on my own form and fitness and not give up hope," said Charteris.
"You want to make the squad, but everyone wants a starting spot and I'm not going to give up on that either, personally, I'm feeling good at the moment and happy with the way I'm playing.
"The Dragons hit some form at the end of last season, there are five of us out here on the camp and there's a real buzz at Rodney Parade at the moment both on and off the field.
"It all feels like it's coming together, we have been talking a lot about redevelopment of the ground over the last few years, but now something has happened there and its really good to see.
"We have bricks and mortar to be proud of and, if that helps bring more crowds in, it can only have a positive impact on our home form.
"The one thing we have over the other regions is all the history that comes with Rodney Parade.
"We aren't moving we are staying there and developing and that's great news for both the fans and the players.
"The next step is to consolidate and then improve our away form and take a little of the magic of Rodney Parade away with us.
"We have shown by our representation on this camp that hard work and endeavour is rewarded.
"If some or all of us can make it into that Rugby World Cup squad then we will come back better players again and that is obviously everyone's aim now.
"But first we have to get into those squads to face England or Argentina and show that we are worthy."
Lydiate agrees that things are on the up for the Dragons, but he too wants to ensure he brings his regional form to the international stage against England (twice) and Argentina next month.
"It's exciting times at the Dragons with the new stand going up and, on the pitch, we've put new systems in place which are paying dividends," said Lydiate.
"We have something to build on next season and it all seems to be coming together.
"But rugby at international level is a different prospect and, with five players from the Dragons in the Wales squad at the moment, it bodes well for our future.
"England, in particular, are a tough prospect. I was surprised just how physical they were when we faced them in our first match of the Six Nations this year.
"I'd faced the Southern Hemisphere sides in the Autumn. I missed the Springboks game, which looked pretty physical, but the Wallabies and the All Blacks games were more fast paced and furious.
"England was that, but more physical again. Perhaps because of the intensity of the Six Nations, but it was certainly an eye opener for me.
"It was the most physical game I have played in and, in that respect, facing them again this August, and Argentina as well, is going to be ideal RWC preparation."
Charteris concurs and he believes that the squad, and himself personally, should be near their physical best by the time the referee blows his whistle at Twickenham next month.
However, he knows the next step is to translate all that hard work into performances on the pitch.
"We've worked hard off the pitch and we have all pushed each other and reached a good physical standard," said Charteris
"I'm fitter than I've ever been, I'm at my ideal weight at 126/127kg, that's as heavy as I can get whilst maintaining my mobility around the pitch.
"I now need to transfer that physical improvement into my game and put my hand up.
"It's not going to be easy as there is competition everywhere you look in the squad, but that will drive us forward and be good for Wales, I only hope I can continue to play my part."
Charteris does have one unusual factor in his favour in the form of his apparent doppelganger, Blues back row Sam Warburton, with both players in top form he wouldn't mind the influence of any extra subliminal messages for the coaches.
"Bizzarely I do keep getting mistaken for Sam by rugby fans when out in public," added Charteris.
"It's happened two or three times now and I wouldn't mind, but the last time it happened I was standing up as well.
"Considering I'm a good seven inches taller than him, it is pretty strange, but I take it as a compliment.
"Sam's playing really well at the moment too so I don't mind the association at all."
Tickets to the Wales vs England Rugby World Cup warm-up match at the Millennium Stadium on Saturday 13 August (kick off 2.30pm) are priced £30 and tickets to the Wales vs Argentina on Saturday 20 August (kick of 2.30pm) are priced at £25 and are on a 'buy one get one free' promotion.
Fans can also purchase their tickets for the Millennium Stadium clashes offer online at www.wru.co.uk/tickets or by calling the ticket hotlines 08442 777 888 or 02920 230130 or at local Tesco stores.