[13] The club had previously occupied four different grounds in the 25 years since their formation in East London; limited expansion space on the Isle of Dogs meant The Lions had to move to boost support and attendances.

[22] The Lions were pushing for promotion to the First Division toward the end of the decade, but one week into the 1939–40 season, World War II broke out and Millwall were robbed of their aim.

[23] The Den sustained severe bomb damage on 19 April 1943, and one week later a fire, determined to have been caused by a discarded cigarette, also destroyed an entire stand.

One highlight of the period was one of the biggest giant-killing upsets in the Fourth Round of the 1956–57 FA Cup on 26 January 1957, when Millwall beat Newcastle United 2–1 in front of a crowd of 45,646.

All the players, which included winger Barry Rowan, goalkeeper Alex Stepney, defender Tom Wilson and strikers Hugh Curran and Len Julians, were presented with a commemorative gold cigarette lighter by the Football Association.

[34] George Graham managed Millwall from 1983 to 1986, and during that time he guided the club to a Football League Group Cup win, beating Lincoln City 3–2 in the final in the 1982–83 season.

In his second season as manager, Millwall won the Second Division championship and gained promotion to the top flight of English football for the first time in the club's history.

[43] Striker Teddy Sheringham, who later played for England and was the highest-scoring player throughout the Football League in the 1990–91 season,[44] was sold to Nottingham Forest for £2 million after Millwall's 6–2 defeat to Brighton & Hove Albion in the Second Division play-offs.

[4] McCarthy resigned to take charge of the Republic of Ireland national team on 5 February 1996, shortly after Millwall had been knocked off the top of the Division One table by Sunderland, following a 6–0 defeat.

[55] The club was missing 16 players from their squad due to suspension or injury, but kept the score at 0-0 until 1 minute before half-time when Gary Neville's cross was headed in by Cristiano Ronaldo.

Midfielder Curtis Weston, substituted for Wise with one minute of normal time remaining, became the youngest Cup final player in history at 17 years 119 days, beating the 125-year-old record of James F. M.

Millwall drew 1–1 with Burnley and wore a special one-off kit for the game, made by manufacturers Macron, which bore the names of every footballer who had played for the club.

[88] In his first full season in charge, Harris led Millwall to a fourth-place finish in League One and a play-off final at Wembley, which the Lions lost 3–1 to Barnsley.

Millwall required a win on the final day of the season to secure a play-off spot but gave up a 3–1 lead, losing 4–3 to Blackburn Rovers and eventually finishing 8th.

Since first becoming involved in the club in 2006, he has presided over some of the greatest moments in Millwall's history, and his influence in providing the platform for those was immeasurable...any success moving forward will be in his memory and honour.

[3] The club did not like the nickname and changed it after press headlined Millwall as 'Lions of the South', after knocking Football League leaders Aston Villa out of the 1899–1900 FA Cup.

[4][125] In September 2016 Lewisham Council approved a compulsory purchase order (CPO) of land surrounding The Den rented by Millwall, as part of a major redevelopment of the "New Bermondsey" area.

[157] The Lions last played against fellow South East London club Crystal Palace in the 2021–22 season in an FA Cup tie at The Den, which resulted in a 2–1 loss.

[37][192] Former club chairman Reg Burr once commented: "Millwall are a convenient coat peg for football to hang its social ills on",[195] an example being the reporting of convicted murderer Gavin Grant.

[197] A local newspaper, East Ham Echo, reported that, "From the very first kick of the ball it was seen likely to be some trouble, but the storm burst when Dean and Jarvis came into collision (Millwall had two players sent off during the match).

"[198] In the 1920s Millwall's ground was closed for two weeks after a Newport County goalkeeper, who had been struck by missiles, jumped into the crowd to confront some of the home supporters and was knocked unconscious.

[194][199] The 1985 Kenilworth Road riot, after an FA Cup sixth-round match between Luton Town and Millwall on 13 March 1985, became one of the worst and widely reported incidents of football hooliganism to date.

[206][207] In January 2009, hundreds of Millwall fans perceived as "high risk" individuals gained access to an FA Cup fourth-round match away at Hull City.

There were conflicting reports in the media as to whether missiles were initially thrown by Hull supporters following chanting and jeering by Millwall fans of Jimmy Bullard (an ex-West Ham player) just prior to the fixture.

[212] After a game against Queens Park Rangers at Loftus Road in September 2010, manager Kenny Jackett said Millwall's hooligan problems are to a certain extent exaggerated by media sensationalism.

This has led to a siege mentality among supporters of the club, which gave rise to the Millwall fans' famous terrace chant, No one likes us, we don't care, being sung in defiant defence of themselves and their team.

[222][223][224] Cabinet minister George Eustice refused to condemn Millwall fans, stating the Black Lives Matter political movement was against what most British people believed in though said the players should be free to express their views.

Some Millwall supporters had said their boos at the Derby game did not have racist intent, but were instead directed specifically at the Black Lives Matter movement, which had become increasingly unpopular with fans.

[266] Millwall have been depicted in films several times, specifically highlighting the club's hooliganism firm the Bushwackers and the rivalry with West Ham United.

The book looks at the rivalry with West Ham United, the stabbing of a Millwall supporter and the Lions play-off success and promotion to The Championship under Kenny Jackett.