Nancy Lesser, HBO’s long-serving head of entertainment PR and talent relations, is leaving the TV powerhouse that she helped build as the steward of campaigns for “The Sopranos,” “Game of Thrones,” “Angels in America” and many other indelible programs.

For industryites, Lesser has become synonymous with HBO, given her wide-ranging role at the company. Lesser confirmed her resignation to HBO staffers on Wednesday. She is the latest senior executive to depart HBO following the management shakeup in March, when Bob Greenblatt was named WarnerMedia Entertainment chairman, prompting the exit of longtime HBO CEO Richard Plepler.

“HBO has been a truly wonderful home for me for the last 35 years,” Lesser said in a statement. “I have had the distinct privilege of overseeing the most creative, dedicated and smartest communications team in television. Additionally, I have been extremely fortunate to be involved with some of the most groundbreaking and relevant programming and to have worked alongside the exceptional talent who created and executed these memorable shows. As I move on from HBO, I will be cheering the ongoing successes of this remarkable company as it continues to lead the industry as the gold standard.”

Lesser joined HBO in February 1984 as a senior publicist in New York. She didn’t intend to stay very long, but 10 years later she relocated to the West Coast as original programming slowly but surely became a bigger focus for the pioneering premium TV network. She rose through the ranks and was most recently promoted to exec VP of media and talent relations in 2016.

To a generation of journalists covering a turbulent industry, Lesser was a constant, a stalwart who knew everything about her network and her shows, backwards and forwards. Some years ago, she achieved one-name superstar status. There was never any question about who was on the line if Nancy (or occasionally “Nance”) was calling. She became well known for her signature bun and affection for high-neck, long black dresses.

Lesser’s departure is another sign of what has been a difficult transition for many at HBO over the past 16 months since AT&T completed its $85.4 billion acquisition of Time Warner. PR functions for HBO and Turner outlets have been consolidated under Kevin Brockman, exec VP of global communications, WarnerMedia Entertainment and direct-to-consumer. Brockman called Lesser “a force of nature” and praised the team she built over her long tenure.

“I’m sure that whatever adventures await Nancy in her next chapter, they will be as rich and rewarding as her time at HBO,” Brockman said.

Here is Lesser’s full memo to HBO staffers:

To: HBO Staff

From: Nancy Lesser

I have always believed that HBO is more than just a special place – it is, in fact, a place unlike any other. I know this because in 1984, as a newly hired senior publicist in New York, I came to the company with the intention of staying just two years to earn the corporate credit on my resume. Little did I know, or even expect, that those two years would surprisingly turn into thirty-five; and become the most meaningful and satisfying time in my professional career. This journey has been an extraordinary one, where I had the great pleasure and privilege of working with the most impressively creative and dedicated people at every level in every department. The long-standing relationships that were built, the teamwork that is pervasive throughout the company, and the unique sense of family have always been an inspiration to me.

In 1994, I traded coasts and relocated to LA with the unwavering support of my exceptional leaders Richard Plepler and Quentin Schaffer (my boss of 28 years), who entrusted me to expand the media relations and talent relations department into one of unparalleled excellence. The camaraderie and bonds formed among this incredible group – east coast and west coast – are emblematic of the HBO spirit and one that I have been so fortunate and proud to be a part of for so many years.

During my tenure, I had the enviable opportunity to work with outstanding producers, writers, directors, and actors; and to oversee so many exceptional, significant and award-winning projects, such as Band of Brothers, The Sopranos, Angels in America, Big Little Lies, Game Change, Recount, The Normal Heart, Behind the Candelabra and Game of Thrones. These, and numerous others, had an enormous impact on the television landscape and were programs for which I was so grateful to have been involved.

As I now move from HBO to my new chapter, the deep-seeded relationships and richly-valued experiences will continue to always be a vital part of my world.

As my dear friend Jerry Weintraub so wisely advised… “This much I knew. As soon as you feel comfortable, that’s when it’s time to start over.”