One of the most storied runs in TV is coming to an end. Richard Plepler is leaving HBO after 27 years with the cable giant, three decades that saw the “Home Box Office” become the premiere generator of prestige TV content and a global brand with few contemporaries. Plepler informed staff of his decision in a Thursday memo. "My dad always gave the best advice," reads the letter Plepler sent company-wide. "Whenever there was a difficult decision to make, he counseled that since no one could ever have perfect visibility into the future, the best thing you could do was trust your instincts. It has been a touchstone for me throughout my life, and I have found myself returning to it again recently as I think about what is an inflection point in the life of this wonderful company. Hard as it is to think about leaving the company I love, and the people I love in it, it is the right time for me to do so." News of Plepler's departure comes nine months after AT&T's $85 billion-$105 billion acquisition of HBO parent Time Warner was approved and finalized, forming WarnerMedia, and days after The Hollywood Reporter reported that Bob Greenblatt is in talks with the company about a big new role — one that would put the former NBC Entertainment chairman in a leadership position atop a sprawling TV portfolio.

The 59-year-old Plepler is said to have reached his decision to leave several weeks ago. Sources cite HBO's shrinking autonomy within the expanded WarnerMedia portfolio as a major motivator and say that Plepler had a "gracious" conversation WarnerMedia CEO John Stankey about departing before the chatter about a new top programming hire at the parent company had started. Plepler joined HBO in 1992, eventually rising to co-president (a role he held from 2007 to 2012) and then chairman and CEO in 2013. Some of his biggest contributions to the pay cabler include giving the green light to such legacy hits as Game of Thrones, Girls and Veep and overseeing the launch of primetime originals at sister network Cinemax and a successful segue into streaming with HBO Go and OTT option HBO Now. Classic cable users, combined with those who exclusively stream, have the current global HBO imprint at just under 130 million subscribers. (Including Cinemax, Plepler's portfolio has over 142 million subscribers.) Recent years have seen HBO's industry dominance challenged by the rise of Netflix, both in the streamer's play of subscribers and prestige. There was a bit of an upset at the 2018 Emmys when Netflix surpassed HBO in nominations, though the two ultimately tied in wins. Plepler and entertainment president Casey Bloys had brushed off suggestions that HBO would need to up its content tally, modest in comparison to Netflix's, but all that changed when WarnerMedia was formed. The network is now looking to ramp up its original offerings in an effort to stay competitive with Netflix, Amazon and umpteen other upcoming streaming rivals.

“richard> “richard> Read the full memo below.

My dad always gave the best advice. Whenever there was a difficult decision to make, he counseled that since no one could ever have perfect visibility into the future, the best thing you could do was trust your instincts. It has been a touchstone for me throughout my life, and I have found myself returning to it again recently as I think about what is an inflection point in the life of this wonderful company. Hard as it is to think about leaving the company I love, and the people I love in it, it is the right time for me to do so. In the past weeks, I’ve thought a lot about the incredible journey of this company in the nearly 28 years that I have been blessed to be here. It’s a journey of great pride and accomplishment because so many of you, and many others before us, have made HBO a cultural and business phenomenon. Thanks to all of you, we are today churning on all cylinders both creatively and as a business. Thanks to all of you, I can move on to the next chapter of my life knowing that the best team in the industry remains here to carry on our continued progress and success. As I have said before, this is the team of teams. It has been the great joy of my professional life to share this ride with you over these many years. And the great honor of my professional life to be your CEO. I don’t have the words to express my gratitude for the support and talent that made our success together possible. But suffice it to say, my love for this place, and for all of you, is deeply a part of me and will last a lifetime. I look forward over the coming weeks to thanking as many of you as I can for the thousands of contributions big and small that have made “this thing of ours,” to quote Tony Soprano, so special. I have told John, who has been nothing but gracious since we spoke, that I would work closely with him to assure a seamless and organic transition.

We’ve created a great and unique enterprise and I know that you will protect its legacy and do all to enhance its future in the years to come. Know that I will always be cheering loudly, even when I am outside this building, as HBO continues to thrive. With respect, admiration, and gratitude,