Dale Steyn has retired from Tests with immediate effect, bringing the curtain down on one of the greatest careers in the longest format and finishing as South Africa's highest wicket-taker. The 36-year-old took 439 wickets in 93 Tests, having overtaken Shaun Pollock earlier this year. He will continue to be available for ODI and T20I selection.

"Today I walk away from a format of the game I love so much," Steyn said. "In my opinion Test cricket is the best version of this game. It tests you mentally, physically, emotionally. It's terrible to consider never playing another Test again but what's more terrifying is the thought of never playing again at all. So I will be focusing on ODIs and T20s for the rest of my career to maximise my full potential and ensure my longevity in this sport.

"I'd like to thank everyone in cricket, no one specific, because everyone has been a part of my journey. And I look forward to continuing to play for the Proteas in the shorter formats. Thank you."

One of the leading Test bowlers of all time, Steyn was ranked the No. 1 Test bowler for a record 263 weeks between 2008 and 2014. He won the ICC's Test Cricketer of the Year award in 2008 and was one of Wisden's cricketers of the year in 2013. In the following year, he was named the almanack's Leading Cricketer in the World. He also featured in numerous ESPNcricinfo World Test XIs over the years.

He overcame a potentially career-ending injury after breaking a bone in his right shoulder during South Africa's tour to Australia in late 2016, returning to Tests 14 months later against India early last year and taking just 14 deliveries to pick up his first comeback wicket.

Another injury - this time to his heel - stalled his progress, but Steyn once again fought his way back to full fitness and, in December 2018, returned to Test cricket. In the Boxing Day Test against Pakistan in Centurion, he became South Africa's leading wicket-taker in the format with his 422nd dismissal, breaking Pollock's ten-year-old record. The full extent of his injury problems was encapsulated on the day - the man with the best strike-rate for bowlers with a minimum of 300 wickets had taken 41 months to go from 400 to 422.

The record marked another major milestone for Steyn, who also returned to ODI cricket for the first time in two years, against Zimbabwe. He was named in South Africa's squad for the 2019 World Cup, but aggravated an old injury in his right shoulder while turning out for Royal Challengers Bangalore in the IPL before the tournament, and was ultimately ruled out.

Steyn has retained his national contract for the 2019-20 season in limited-overs cricket, however, and remains available for selection in both of the shorter international formats.

But his absence from the Test arena will put a major dent in South Africa's resources for their upcoming engagements - an away Test series in India in October, before they host England this summer. Without him, South Africa's pace attack will be lead by Vernon Philander and Kagiso Rabada, while there may also be greater opportunities for Lungi Ngidi, and perhaps even a Test debut on the cards for Anrich Nortje.

"Dale is undoubtedly one of the all-time greats of cricket," said Cricket South Africa chief executive Thabang Moroe. "From the time he made his Test debut against England in 2004 and dismissed their captain, Michael Vaughan, with a superb delivery, he has been one of the standout fast bowlers in world cricket. He has led the South African attack brilliantly and has set the standard for our future generations to follow.

"More than that he has been a wonderful mentor to our next generation of speedsters. We were saddened to hear of his decision, but it is one that management has to accept, and we thank him for his significant contribution to the sport and to the nation and wish him everything of the very best for the future."

In the immediate future, Steyn will play in the Euro T20 Slam, where he was recently picked up as a marquee player by the Glasgow Kings franchise.