How Illustrious-class carrier delays accumulated

The ordering, laying-down, launching, and commissioning dates of Illustrious, Formidable, Victorious, and Indomitable show how the delays accumulated. Some delay came from shipyards learning to build a new design, but the gaps widened after carrier construction slowed at the start of the war. Victorious was laid down only about a week after Illustrious, yet she commissioned roughly a year later. The comparison shows how a decision affecting ships already under construction postponed essential fleet aviation.