Star Trek: 10 Things You Didn't Know About Jean-Luc Picard
3. Picard Played A Pivotal Role In Trying To Stop The Romulan Supernova - Multiple Times
Star Trek: Picard established on-screen that the captain, and later admiral, was instrumental in attempting to save the Romulans from the impending supernova. In this reality, the Zhat Vash organise for the Synths on Mars to revolt, killing thousands of people, and destroying the rescue armada. In the wake of these events, Picard steps away from Starfleet.
The supernova itself originated in Star Trek 2009, acting as the catalyst for the entire Kelvin-universe. The four-part miniseries, Star Trek: Countdown, depicts the events that result in Spock's time travel, with Picard playing a pivotal role. In this reality, Picard was the Ambassador to Vulcan, with a revived Data, in B-4's body, serving as captain of the Enterprise-E.
Picard then, with Ambassador Spock, petitions the Vulcan High Council to deliver Red Matter to the Romulans, which would protect them against the nova. Despite much debate, the High Council denies the request. This directly leads to Nero's descent into madness, almost results in Worf's death, and leaves the Enterprise-E crippled after a fight with the Narada.
The comic closes with Picard discovering the fading singularity, the one responsible for sending both the Narada and Spock back in time, with Picard sadly realising they've lost Spock forever.