The two former powerhouses are joined in the Championship by fellow ex-heavyweights Aston Villa and Nottingham Forest. Is there any hope for a romantic revival in fortunes?
Four fallen giants of English football duke it out in the Championship this weekend: Newcastle United host Nottingham Forest on Friday (kick-off 19:45 UK time) and Leeds United welcome Aston Villa on Saturday (17:30 KO).
Goal takes a peek at the history of these former heavyweights, explains how they fell on hard times, and looks at their chances of a return to greatness.
Why are Newcastle a fallen giant?
One of the defining clubs of the Premier League era - particularly in the 1990s and early 2000s - Newcastle United were twice runners up to Sir Alex Ferguson's Manchester United in 1995-96 and 1996-97.
Just seven clubs have won the FA Cup more times than the Magpies (six), but they have not lifted England's premier trophy since 1955. They came tantalisingly close in 1997 and 1998 but were beaten at Wembley in the final by Arsenal and Man Utd respectively.
In fact, the only silverware they have won in the last 50 years are two second division titles (1992-93 and 2009-10). However, a stadium that holds over 50,000 supporters, a passionate fanbase, and extravagant signings have kept them rooted in prestige.
Who are Newcastle's legends?
Malcolm Macdonald was a goalscoring machine in the 1970s for Newcastle and is revered on Tyneside. So too is Jackie Milburn, who scored 200 goals for Newcastle in the 1940s and 1950s.
Newcastle broke the world record transfer fee (£15 million) in 1996 to sign Alan Shearer, who spent a decade scoring 206 goals for his boyhood club. Paul Gascoigne only spent three years at the club after making his debut aged 17 in 1985 but remains intrinsically linked with the city of Newcastle.
How did Newcastle fall on hard times?
At the start of 2016 Newcastle United were ranked the 18th-richest club in the world but a shocking season saw them relegated from the Premier League, with Rafa Benitez unable to save them from the drop having been parachuted in with 10 games to go.
Realistically, they have been a shadow of their former selves for a decade. One incredible campaign in 2011-12 where they almost finished fourth does not disguise the fact that owner Mike Ashley has failed to rekindle their halcyon days.
Is there hope of a return to greatness for Newcastle?
The last time they dropped into the Championship, in 2009, they bounced straight back up at the first attempt, and that is certainly what they're favourites to do in 2016-17 too.
Against all expectations, Benitez stayed at St James' Park and he has forged an illustrious squad sits top of the Championship with 18 games played. They host Forest having been surprisingly beaten by Blackburn a week ago and knocked out of the EFL Cup on penalties by Hull City, so they'll be hoping this is only a soon-to-be-rectified form wobble
Why are Nottingham Forest a fallen giant?
Back-to-back European Cup final victories in 1979 and 1980 cemented their legendary status in English football folklore. Their first title was completely unexpected, so imagine Europe's collective shock that this previous unknown stormed the continent twice.
They have only won the English top flight once, in 1977-78, but what an incredible campaign it was. Newly-promoted under Brian Clough, they stormed to a fairytale victory that was used as a constant comparison during Leicester's title win earlier this year.
Forest have won four League Cup finals and two FA Cup finals, although it has been 26 years since their last major silverware triumph.
Who are Forest's legends?
Nobody casts a bigger shadow over Nottingham Forest's history than Clough, who managed the club between 1975 and 1993. He took them from underachievers to European champions without massive financial backing. John Robertson - who scored in the 1980 European Cup final - and Ian Bowyer are two club legends from Clough's era, claiming over 1,000 appearances between them.
Stuart Pearce is probably the most iconic player for them in the past 25 years. The England defender racked up over 500 appearances for the club and helped them to two League Cup victories and one FA Cup final defeat. Roy Keane and Martin O'Neill also played for Forest under Clough.
How did Forest fall on hard times?
Forest have been relegated from the Premier League three times since its inauguration, most recently in 1999. They spent a lot of money in an effort to return to the top flight and, when it proved unsuccessful, left themselves with serious financial problems.
In 2003-04, they suffered the ignominy of becoming the only European champions to fall into the third tier. Four years later they returned to the Championship and that's where they've remained since then - occasionally flirting with promotion but yet to succeed in climbing the league ladder.
Is there hope of a return to greatness for Forest?
In 2012 the club were bough by the Al-Hasawi family and there's been lingering hope that they could return to the top flight for the first time since 1999.
Forest are seven points off the play-off zone with 18 games played, but also only four points off second-bottom. Promotion isn't looking likely at this stage of the season, but the topsy turvy nature of the league means it's impossible to rule anything out until after the Christmas period.
Why are Leeds United a fallen giant?
Leeds' golden era began with the appointment of Don Revie as coach in 1961. During his 13-year reign Leeds topped the first division twice, finished runners up five times, won the FA Cup once, the League Cup once and reached the final of the European Cup.
Like Newcastle, they benefit from being the only club in a big city, meaning they have an enormous fanbase. Elland Road, with its capacity in excess of 37,000, is one of the largest in the country.
They last finished winners of the first division in 1992 - the last campaign before the Premier League began. They remained one of the biggest teams in the division and reached the Champions League semi-finals in 2001, but they completely imploded financially from 2001, leading to their relegation in 2004.
Who are Leeds' legends?
Billy Bremner, Peter Lorimer, Allan Clarke and Eddie Gray are among the many club legends that emerged during Revie's era, who of course became a hero at the club due to the success he brought to Elland Road.
More recently, Leeds can count Gordon Strachan, Gary McAllister and Lucas Radebe among their club icons. Avid football fans over 20 will vividly remember the likes of Mark Viduka, Jonathan Woodgate, Hary Kewell and Alan Smith impressing for Leeds towards the end of their Premier League years.
How did Leeds fall on hard times?
Leeds had never played lower than the second division of the English football structure but, when they entered administration due to being wrecked financially in 2007, they suffered relegation to the third tier for the first time.
They spent three years slumming it in League One before returning to the Championship, where they have not been realistic promotion contenders since their return.
Is there hope of a return to greatness for Leeds?
Whisper it, but maybe - just maybe - this is finally their year. Garry Monk has hauled them into the play-offs after a sloppy start to the campaign and they are one of a handful of clubs contending for promotion.
It is a long season and, with less than halfway gone, Leeds fans won't be counting their chickens for a long time yet after over a decade of hard times.
Why are Aston Villa a fallen giant?
Aston Villa were one of the most successful clubs early in English football's existence. They won six first division titles between 1894 and 1910. Since then they have topped the first division just once, in 1980-81, but they followed that up with European Cup glory back when English clubs couldn't stop winning the trophy.
Only Everton (114 years) have spent more time in the top flight of English football than Aston Villa (105 years).
Villa have won the FA Cup seven times and the League Cup five times. They finished runners up to Man Utd in the first Premier League season (1992-93) and were regularly fighting for places in the top six until around 2010 when relegation battles became commonplace.
Who are Villa's legends?
So many of Aston Villa's most decorated league champions played over 100 years ago, before the First World War.
Post-World War II, the Birmingham-based club can count all-time appearance holder Billy Walker among their greatest ever. Gary Shaw was their star striker as Villa romped to league and European Cup glory in the 1980s.
In recent years Gareth Barry, Dwight Yorke and Steve Staunton have been at the heart of the club's Premier League efforts, while Paul McGrath is regarded by many of Villa's faithful as their best-ever player.
How did Villa fall on hard times?
American investor Randy Lerner's purchase of Villa in 2007 was at first seen as a huge positive for the old club, but as his stewardship of the British club went on his interest clearly waned.
Martin O'Neill, Gerard Houllier, Alex McLeish, Paul Lambert, Tim Sherwood and Remi Garde all came and went as Villa sank towards relegation earlier this year.
Is there hope of a return to greatness for Villa?
Villa really spent big in the summer in a bid to bounce back from their Premier League relegation. Roberto Di Matteo's men simply couldn't turn draws into wins and the Italian was dispatched.
Steve Bruce was hired and Villa haven't lost in seven games, leaving them four points off the play-off spots. As ever, competition for promotion into the Premier League will be fierce, but Bruce has experience on his side and one of the most expensively assembled squads ever to grace the second tier.