Ireland will kick off their Six Nations title defence today as they host England in a mouthwatering opening weekend clash in Dublin.

The men in green are chasing an unprecedented third successive title but are without head coach Andy Farrell, who has stepped away from his role for this tournament to focus on preparations for this summer's British & Irish Lions tour to Australia.

Simon Easterby will lead the side as interim head coach and has been handed a tasty first challenge in the role, with England putting an end to Irish Grand Slam hopes in dramatic style when they met at Twickenham a year ago.

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Steve Borthwick's side will also be looking to get off to an impressive start, with fans set for an exciting and eventful 80 minutes of rugby at the Aviva Stadium.

Tasked with keeping the game under control is New Zealander Ben O'Keeffe. Here's everything you need to know about today's referee.

Who is Ben O'Keeffe and what is his other job?

O'Keeffe started refereeing at the age of 19, turning professional five years later, and last year became New Zealand's most capped Test referee in history.

He has also won the New Zealand referee of the year award three times and has officiated at two World Cups.

However, while he has been recognised as one of the best rugby referees in the world, O'Keeffe also leads a very different life away from the rugby pitch.

The 36-year-old is a qualified ophthalmologist, a doctor who cares for patients with eye conditions. He co-founded oDocs Eye Care which aims to create technology which can prevent blindness.

"Certainly, no one can question my eyesight," he said previously. "I’m an ophthalmologist. I’ve been lucky enough to balance both careers over the last couple of years as being a professional referee has become a full-time commitment.”

However, as well as that, O'Keeffe also uses his medical skills to provide anti-wrinkle treatment services, administering Botox and Sunekos injections at his clinic in Auckland.

In an Instagram post in December, the referee explained: "Over the summer I use my medical skills as a doctor before rugby ramps up again. Anti-wrinkle treatment is here and I am happy to help you tailor the look that you want. Especially for the bro’s who have never tried it and want to see what all the fuss is about #brotox"

Also away from the field, O'Keeffe got engaged to journalist Wilhelmina Shrimpton in the autumn, as he popped the question on a trip to South Africa. Shrimpton, a newsreader and writer in New Zealand, previously worked with the referee's brother before following her now-fiance on Instagram.

The couple regularly share loved-up snaps of them enjoying romantic holidays together, having recently spent the start of the new year in Thailand. They are now preparing for their wedding, with O'Keeffe admitting he has long wanted to settle down.

“I’ve always wanted a family. I’ve always wanted a house where you can just settle down and be happy," he said earlier in their relationship. "But I’ve always wanted to do that with the right person, so I’ve waited. Now I’ve found Wilhelmina, I’m sure all of that stuff will happen."

Scary fan encounter in toilet

On the pitch, O'Keeffe has copped more than his fair share of flak, with the 2023 Rugby World Cup in Paris seeing put him under strain and even confronted by an angry fan in public.

The New Zealander was selected to take charge of the highest-billed match at the tournament as South Africa faced France in a blockbuster quarter-final, which finished 29-28 to the Springboks. But while the dramatic match had everything, with some of the world's best players on display, it was O'Keeffe who attracted much of the bad press afterwards.

Flashpoints in the match included Springbok star Eben Etzebeth avoiding a red card for a hit on Uini Atonio, Damian de Allende receiving no punishment for an apparent forearm to the head of Antoine Dupont and Kwagga Smith escaping a penalty against him after illegally forcing a crucial turnover at the breakdown.

At the full-time whistle, a frustrated Dupont claimed O'Keeffe and his team were "not up to the level" required for such an important occasion, adding: “It’s hard to talk about these things because there’s lots of disappointment and frustration. We could have had some penalties at crucial moments.

"I don’t want to be a bad loser and moan about the refereeing but I don’t think the refereeing was up to the level of what was at stake. It’s not just one person, there are TMOs, assistant referees and they have time to review images as the game is going on. This doesn’t take anything away from South Africa’s performance, they played a great game."

O'Keeffe dismissed Dupont's comments, saying that he understood they had been made "in the heat of battle" and at "a very emotional time." However, the impact that the match had on the referee was significant as the brutal days that followed saw him confronted by home fans and left him feeling scared being out in public.

During RugbyPass's Whistleblowers documentary, the referee admitted the week that followed was "one of the toughest I've ever had in my life", adding: "I did feel scared around being in public, I just didn't want to lock myself in my room though. I was starting to second guess, like can I actually go out in public now?

"In the meantime, I'm trying to prepare for the biggest game I've ever been involved in. It took me a lot to get my head in the right space. To be hated by a nation isn't nice."

In a video series by the All Blacks on mental health and rugby, he later explained. "We knew as referees going into that game that there was going to be controversy no matter what. I guess I hadn't really prepared myself for the level of criticism and the onslaught that came in afterwards.

"I'd done the semi-final and I was actually in the bathroom and someone came up to me and asked me if I was Ben O'Keeffe. I said yes and he said 'look, I told my friends if I ever saw Ben O'Keeffe in real life I was going to kill him.

"I was in a corner of this bathroom, cornered by this person and three other people and I just got out of there. Those sort of moments really affected my mental wellbeing and my mental health. I started questioning myself again."

Ireland v England referees

• Referee: Ben O’Keeffe (New Zealand)

• Assistant referee 1: James Doleman (New Zealand)

• Assistant referee 2: Hollie Davidson (Scotland)

• TMO: Glenn Newman (New Zealand)