Sep 24, 2007 CE
Pilot Episode
Leonard Hofstadter and Sheldon Cooper, physicists at Caltech, meet their new neighbor Penny, a waitress and aspiring actress. Leonard develops a crush on her. #sitcom #tbbt
Chronological Storyline (37 Milestones)
Oct 8, 2007 CE
Howard and Raj Introduced
Howard Wolowitz and Raj Koothrappali are introduced as part of the group. Raj is unable to speak to women unless he drinks alcohol. #tbbt
Nov 12, 2007 CE
Sheldon's Spot on the Couch
Sheldon's obsessive-compulsive need for his specific spot on the couch is established, becoming a running gag. #tbbt
Jan 14, 2008 CE
Leonard and Penny's First Kiss
Leonard and Penny share their first kiss, marking a major step in their relationship. #tbbt
May 5, 2008 CE
Sheldon's 'Bazooka' Shotgun
Sheldon attempts to build a quantum physics experiment and accidentally destroys Penny's TV with a 'bazooka' shotgun. #tbbt
Sep 22, 2008 CE
Stuart Bloom Introduced
Stuart Bloom, owner of the comic book store, is introduced as a frequent acquaintance of the group. #tbbt
Oct 6, 2008 CE
Leonard and Penny Date
Leonard and Penny go on their first official date, which ends with them becoming a couple. #tbbt
Dec 15, 2008 CE
Howard's Date with Leslie Winkle
Howard goes on a date with Leslie Winkle, but it ends poorly. #tbbt
Mar 9, 2009 CE
Sheldon Wins 'Time' Magazine Quiz
Sheldon discovers he was featured in Time magazine's '100 Most Influential People' but as a result of a prank. #tbbt
Sep 21, 2009 CE
Penny and Leonard Break Up
Penny breaks up with Leonard after recognizing their differences, but they remain friends. #tbbt
Nov 9, 2009 CE
Howard in Space (Simulated)
Howard participates in a simulated space mission for NASA, but the simulation goes awry. #tbbt
Jan 11, 2010 CE
Sheldon Meets Amy Farrah Fowler
Sheldon is matched with Amy Farrah Fowler on a dating site. She becomes his girlfriend, though their relationship is initially platonic. #tbbt
May 24, 2010 CE
Howard Proposes to Bernadette
Howard proposes to Bernadette, but she initially says no due to his immaturity. Later she accepts off-screen. #tbbt
Sep 23, 2010 CE
Howard's Real Space Mission Announced
Howard is selected for a real NASA mission to the International Space Station. #tbbt
Feb 10, 2011 CE
Sheldon and Amy's First Kiss
Amy forces Sheldon to kiss her, which he reluctantly does. It's a milestone in their relationship. #tbbt
Apr 7, 2011 CE
Howard Goes to Space
Howard launches to the International Space Station, fulfilling his lifelong dream. #tbbt
Sep 22, 2011 CE
Leonard and Priya Koothrappali
Leonard dates Raj's sister Priya, but Penny is jealous. #tbbt
Feb 2, 2012 CE
Howard's Wedding to Bernadette
Howard and Bernadette get married, with Howard's mother interrupting the ceremony. #tbbt
Apr 5, 2012 CE
Sheldon Learns about Emilia Earnshaw
Sheldon discovers that Amy once had a crush on a fellow scientist, causing him to feel jealous for the first time. #tbbt
Sep 27, 2012 CE
Penny and Leonard Rekindle
Leonard and Penny resume their relationship after a long separation. #tbbt
Jan 10, 2013 CE
Sheldon's Birthday Gift for Amy
Sheldon gives Amy a 'relationship agreement' as a birthday present, showing his unique way of showing affection. #tbbt
Apr 4, 2013 CE
Raj Finds a Girlfriend
Raj begins dating Emily, but his selective mutism still plagues him. #tbbt
Sep 26, 2013 CE
Sheldon and Amy's First Fight
Sheldon and Amy have their first real argument when Amy wants more intimacy. #tbbt
Mar 13, 2014 CE
Howard's Mother Dies
Howard's mother passes away off-screen, causing Howard to grieve. #tbbt
Sep 22, 2014 CE
Sheldon's Train Problem
Sheldon goes on a cross-country train trip after being frustrated with the group, but returns when Amy convinces him. #tbbt
Mar 12, 2015 CE
Penny and Leonard Get Married
Penny and Leonard get married in a small ceremony in Las Vegas, with Sheldon and friends present. #tbbt
Sep 21, 2015 CE
Sheldon Proposes to Amy
Sheldon proposes to Amy in a romantic gesture, though the proposal is unconventional. #tbbt
Feb 18, 2016 CE
Sheldon's Brainwave
Sheldon has a breakthrough in his secret research, leading to a new field of study. #tbbt
Sep 19, 2016 CE
Sheldon and Amy's First Kiss as a Couple
Sheldon and Amy share a passionate kiss, showing their relationship has deepened. #tbbt
Feb 23, 2017 CE
Howard and Bernadette's Baby
Howard and Bernadette welcome their first child, a girl named Halley. #tbbt
Sep 25, 2017 CE
Sheldon and Amy Buy a House
Sheldon and Amy decide to buy a house together, marking a new chapter. #tbbt
Dec 14, 2017 CE
Sheldon and Amy Get Married
Sheldon and Amy get married in a wedding ceremony organized by the group, with Sheldon's mother and other family present. #tbbt
Sep 24, 2018 CE
Sheldon and Amy's Paper Accepted
Sheldon and Amy's joint paper on 'super asymmetry' is accepted for publication, leading to Nobel Prize considerations. #tbbt
Jan 31, 2019 CE
Raj's Engagement
Raj gets engaged to Anu, but later they break up. #tbbt
Mar 21, 2019 CE
Sheldon and Amy Win the Nobel Prize
Sheldon and Amy are awarded the Nobel Prize in Physics for their work on super asymmetry. #tbbt
Apr 18, 2019 CE
Nobel Prize Ceremony in Stockholm
Sheldon and Amy travel to Stockholm to receive the Nobel Prize, with all friends and family attending. Sheldon gives a heartfelt speech. #tbbt
May 16, 2019 CE
Series Finale: The Stockholm Syndrome
One year after the Nobel, the group gathers for dinner. Leonard and Penny announce they are expecting a child. The series ends with the friends sharing a meal. #tbbt