Preston made their piece of history in a 12-team league and a 22-match season. Arsenal romped through a 38-game season with 26 wins and 12 draws. No wonder manager Arsene Wenger said that his players had achieved "footballing immortality".
Arsenal had to show character again, after Leicester led 1-0 at half-time. Tireless ex-Gunner Paul Dickov headed in Frank Sinclair's far-post cross to give the relegated side a shock lead.
Wenger pushed Ashley Cole forward after the break and the move paid immediate dividends. Bergkamp carved Leicester open and Sinclair hauled down Cole as he shaped to shoot.
Henry sent Ian Walker the wrong way from the penalty spot for his 30th Premiership goal of the season.
Footballer of the Year Henry said: "People will still be talking about this in 20 years. We'll enjoy it now - but I think we'll only fully appreciate how much we've achieved when we've retired and we can look back over our careers."
Arsenal could have scored more. Walker saved low from Henry, sub keeper Danny Coyne denied Freddie Ljungberg and Edu's effort was blocked in a scramble.
Veteran Martin Keown, 38 in July, made his last competitive appearance for the Gunners as an 87th-minute substitute, to collect his third championship medal.
Leicester boss Micky Adams said: "We were the bit-players at Arsenal's party. We did our best to frustrate them."
Better teams than Leicester have tried and failed throughout the Premiership season.