On Sunday, and against long odds, Neil Warnock got his eighth promotion. That particular landmark – a record in English football – had become his raison d’etre, a personal obsession he pursued for seven years. Cardiff City delivered it and with the Premier League about to indulge him once more, Warnock classed this promotion the “best achievement” of his managerial career.

Over the course of that career he has had his share and Leeds United, where Warnock rolled up in optimistic mood in 2012, stick out as the club he failed to crack. Where Cardiff and others were made to smile, Warnock’s tenure at Elland Road was bitter, poisonous and doomed to end in acrimony; a period which created a chasm in the relationship between Warnock and the crowd. “It would appease the fans if I go now,” Warnock said after he and Leeds called it quits on April Fools’ Day in 2013.

His appointment 13 months earlier was a marriage of convenience, creating an odd couple. Warnock, who was out of work, had never enjoyed much popularity in Leeds but he held a track record of promotions with Huddersfield Town, Plymouth Argyle, Sheffield United and Queens Park Rangers. His arrival was a last throw of the dice by Ken Bates, an obvious choice for an owner who was beset by public pressure and reluctantly coming round to the idea of selling Leeds. The club were no closer to the Premier League than they had been when Bates took control in 2005.

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Bates called the appointment “arguably the most important we have made.” An enthusiastic Warnock said he had “one big challenge left in me.” For all his experience he did not foresee the scale of it. He inherited a mid-table Championship squad and set about altering it in the same summer that Bates began negotiating a full takeover. Money was tight – too tight to fund the £400,000 signing of Portsmouth right-back Joel Ward, a player who would go on to reach the Premier League with Crystal Palace – and Warnock was left to wheel and deal.

Adam Clayton was sold to Huddersfield Town to raise half a million pounds. Andy Lonergan’s exit allowed Warnock to bring in his favoured goalkeeper and long-time ally Paddy Kenny. Portsmouth were in financial trouble and embarking on a firesale. Leeds dived into it by recruiting Jason Pearce, Jamie Ashdown, David Norris and Luke Varney. Varney was a supposed replacement for Robert Snodgrass who Leeds sold to Norwich City while Warnock and his squad were on a pre-season tour of Cornwall.

Warnock had planned to make Snodgrass captain and build his team around him but without the Scot, Leeds were predictable and one-dimensional. At the very start of the 2012-13 season, Warnock took a risk by handing a short-term contract to El-Hadji Diouf. Warnock was short of a striker and a winger. In the absence of serious cash, Diouf ticked both boxes.

In the background Bates’ proposed sale of Leeds to Gulf Finance House, a little-known Bahraini investment bank, rumbled on as the club stood still. By November 2012, and with United well down the Championship table, Warnock was resigned to the season slipping away. “I get frustrated because if I was 10 years younger then there’s always tomorrow,” he said, “but I want to do it today. You’re almost in a straightjacket. The club’s got to move on, the sooner the better.”

Cardiff City manager Neil Warnock celebrates his side's promotion to the Premier League on Sunday.

At that stage, Warnock’s predicament generated some sympathy. GFH finally agreed its buy-out on November 21 and, helped by the quick loan signings of Alan Tate and Jerome Thomas, Leeds found some form before Christmas, reaching the quarter-finals of the League Cup and making up a little ground in the Championship. But the January transfer window brought more problems. Warnock wanted to sign Chris Wood from West Bromwich Albion but could not afford his fee. Leicester City did the deal instead.

In the eyes of United’s support, performances like that caught up on Warnock. He was targeted by a mutinous away end during a 2-0 loss at Barnsley on January 12, a result which typified his team’s inconsistency. There were other battles too. Warnock took issue with the academy staff at Thorp Arch, complaining later of a “them and us” scenario and accusing those staff of taking pleasure from the first team’s failings. “It’s like a cancer in the club,” he wrote in his autobiography. By the end of the transfer window, Luciano Becchio – a cult hero and the club’s top scorer – had been sold to Norwich in exchange for Steve Morison and £200,000. Warnock promised that Morison would become “a legend”. The striker scored five times in 41 games and found no love in Leeds. Bit by bit, the wheels came off. Ross Barkley, Everton’s rising star, came in on loan but left a month later, somehow surplus despite his talent.

Tom Lees, United’s young centre-back, was castigated for a first-half red card during a 3-0 defeat to Ipswich Town at the end of March, sent off for committing a professional foul after a weak goal-kick from Paddy Kenny. Warnock called Lees “stupid” and accused him of “letting everyone down”. Bates, who was still club president, heard the comments and phoned Lees to console him. Divisions in the dressing room were painted more clearly two days later when, in Warnock’s last match, Ross McCormack aimed expletives at him after coming off the bench to score in a 2-1 loss to Derby County. GFH had decided in advance that defeat to Derby would end Warnock’s tenure. He was sacked within minutes of the final whistle.

It was and is a period like no other in his career, a rare occasion where Warnock found himself at a loss. If Cardiff City are his greatest achievement then Leeds United go down as his greatest disappointment, a club impervious to the ways and means which continue to pay off at the age of 69.