In 2003/04, Arsenal did what no team had done in 115 years, going an entire season unbeaten.
Twenty six wins. Twelve draws. Zero losses.
If the cold statistics sealed immortality, the brand of football won hearts.
Ruthless, swashbuckling, Arsenal's brand of quick passing was married to a cold steel that meant they finished as the season's most potent attack and tightest defence.
Led by Arsene Wenger, captained by Patrick Vieira, spearheaded by Thierry Henry, the team terrified opponents and revolutionised the Premier League.
Unbeaten. Invincible. And forever written into footballing legend.
Also in this series
Part 2: PL30: Test your knowledge on Arsenal's Invincibles
Part 3: PL30: Are Arsenal's Invincibles the PL's best-ever team?