Emlyn came from Treherbert in the Rhondda, He could have been a boxer but fortunately chose rugby and was noted as one of the best stand-offs in British Rugby League in the 1930s. A star of the famous Salford team, coached by Lance Todd, he won virtually every honour in the game (246 appearance 88 tries) before his move to Wigan in 1937-38. He was the star of the 1936 Australian tour, his clashes with the powerful Aussie stand-off Vic Hey were the stuff of legend. One Australian critic wrote that Jenkins undoubtedly surpassed himself and rose to magnificent heights. He was also described as the outstanding player in all three Tests and despite the difference in weight he held Hey in defence and tricked the Australian inside men repeatedly with skilful and varying tactical moves. Emlyn was also noted as a powerful tackler.
Emlyn played several matches for the Saints during the War Years, although given the nature of the times, he would have also turned out for other clubs too. According to Robert Gate, Emlyn actually turned out occasionally at the age of forty and over at the highest level. He held the coaching reigns at St.Helens from 1950-52, until succeeded by fellow-Welshman Jim Sullivan in June 1952 when Jim became Saints first full time manager. In 1951 he turned out at full-back in a match for the Saints against the Players Union, which was a Testimonial game for flying winger Sonny Doyle.
Emlyn Jenkins laid the foundations for a more thoughtful, professional approach for the remainder of the 1950s under Jim Sullivan. Needless to say, it was only a case of fine-tuning by Sullivan which turned the Saints into a major rugby league power. Emlyn passed away in October 1993.