What was the most significant moment in the history of Barney and Robin's break-up on How I Met Your Mother?

Barney and Robin's break-up on How I Met Your Mother was a pivotal moment in the show. After getting married, their relationship began to fall apart due to their individual ambitions and personal issues. The most significant moment in their break-up came in the episode titled 'Last Forever: Part Two,' when it was revealed that they got a divorce three years after their wedding.

Barney and Robin had been struggling with their marriage for some time, and the reveal of their divorce was a shock to fans of the show. It was a heart-wrenching moment that demonstrated the complexities of their relationship and the challenges that they faced as a couple.

This moment marked the end of an era for How I Met Your Mother, as it closed the book on one of the show's most beloved couples. While it was a sad moment for fans, it also allowed the characters to move forward and grow, which was an essential part of the show's narrative.