Alastair Cook ended his reign as England’s longest-serving Test captain and ushered in a new era under his expected successor, Joe Root, after questioning whether he still had the energy to lead the team into next winter’s Ashes. Cook, 32, had been considering his position since the team’s 4-0 defeat to India before Christmas and on Sunday evening he formally tendered his resignation to Colin Graves, the chairman of the England and Wales Cricket Board, before informing the players via email and a series of follow-up phone calls. n calling time on his 59 Tests in charge – a four-and-a-half year spell which featured 24 wins and 22 defeats – Cook stated his intention to continue a career that has reaped 11,057 runs. Cook first met with Andrew Strauss, the director of England cricket, to discuss his future on 13 January but despite being encouraged by his predecessor to take more time to consider his position, the genie was already out of the bottle. Despite making Root vice-captain in May 2015 and though there are few other alternatives to be captain, Strauss held off from confirming his promotion, instead stating he would hold conversations with the selectors, the coaching staff and senior players before making an announcement before the one-day side depart for the Caribbean on 22 February. Cook, who won eight and lost just four of his 17 series in charge and whose highlights included two Ashes victories at home in 2013 and 2015, and away successes in India in 2012 and South Africa last year, has previously endorsed Root’s captaincy credentials. But with only three matches as captain at Yorkshire, and the fact Root will need to juggle his career as a three-format cricketer and a new father, there remain concerns about overburdening the 26-year-old. The first of seven Tests this summer against South Africa and West Indies is not until 6 July at Lord’s, however, meaning there is time to adjust to the role before forging a side to defend the Ashes in Australia, starting at the Gabba in Brisbane on 23 November.