This page only reveals the most important parts fo the Cahill timeline and those more prominent in the 39 Clues series, as all the significant historical events involved with the Cahill family are innumerable.

• 1200s/1300s: Madeleine "the Matriarch" found Cahill Island.
• 1455: Damien Vesper is born.

  

• 1460: Gideon Cahill is born.
• 1464: Olivia Cahill is born.
• 1482: Gideon Cahill and Olivia Cahill marry.
• 1484: Luke Cahill is born.
• 1492: Katherine Cahill is born.
• 1494: Thomas Cahill is born.
• 1497: Damien Vesper and Gideon Cahill become friends. Jane Cahill is born.
• 1507: The Cahill Fire. Luke and Jane go to England, Thomas and Katherine go to Portugal. Madeleine Cahill is born later that year.
• 1510: Jane Cahill becomes an acclaimed English poet and founds the Janus Branch. In that year, also Katherine steals a Clue from Thomas and sails to Egypt to found the Ekaterina Branch and to leave Thomas swearing revenge.
• 1514: Thomas settles in Japan and builds the first Tomas stronghold.
• 1515: Winthrop Cahill is born, the Lucian Branch is founded.
• 1526: Olivia Cahill is killed by the Vespers, Madeleine Cahill founds the Madrigal Branch.
• 1923: Gordon Oh and Bae Oh are born.
• 1927: Beatrice Cahill is born.
• 1929: Grace Cahill is born.
• 1941: Fiske Cahill is born, Edith Cahill dies and James Cahill abandons his children.
• 1942: Grace Cahill goes to Casablanca, where General S. Patton steals Gideon's Ring, only to have Grace steal it back. Alistair Oh is born.
• 1948: Gordon Oh is assassinated.
• 1955: Fiske Cahill goes on the world first nuclear world submarine to keep the ring safe.
• 1959: Arthur Trent is born.
• 1960: Hope Cahill is born.
• 1964: Irina Spasky and Isabel Kabra are born.
• 1990: Ted, Ned, and Sinead Starling are born.
• 1993: Hamilton Holt and Jonah Wizard are born.
• 1994: Amy Cahill and Ian Kabra are born.
• 1997: Dan Cahill, Natalie Kabra, Madison and Reagan Holt are born.
• 2001: The Trent Fire. Hope Cahill and Arthur Trent are killed in the fire.
• 2008: Grace Cahill dies of cancer, The Clue hunt occurs, with Dan and Amy Cahill finding all 39 Clues. Irina Spasky dies.
• 2009: Amy inherits Gideon's Ring.
• 2010: Massive Cahill abduction begins. Natalie Kabra, Phoenix Wizard, Nellie Gomez, Fiske Cahill, Reagan Holt, Alistair Oh, Ted Starling and later Atticus Rosenbloom are kidnapped by the Vespers and Amy and Dan start searching for the mysterious items the Vespers want in order to "release" the hostages. Alistair, Natalie, Isabel and Evan died.
• 2011: Founders Media attacks Amy and Dan Cahill at William McIntyre's funeral.