Watch: Taylor Swift offers rare glimpse into private life in new trailer for Miss Americana documentary

Taylor Swift has released the first trailer for her highly anticipated documentary Miss Americana, promising a rare insight into her personal life.

The 30-year-old superstar shared the clip on her Instagram with the caption, "It's been a long time coming."

It looks like the film will document Swift's transition from country sweetheart to pop icon.

It will also look into her highly publicised - and criticized - break ups with fellow stars Calvin Harris and Tom Hiddleston, as well as giving us a glimpse into her current relationship with Joe Alwyn which for three years, the pair have managed to keep mostly to themselves.

Unexpectedly, the documentary also promises to get political - just as Taylor herself has been recently - as she speaks about the freedom of "not feeling muzzled anymore".

In a voiceover for the trailer, she says: "Throughout my whole career, label executives would just say, 'A nice girl doesn't force their opinions on people, a nice girl smiles and waves and says thank you.'

"I became the person that everyone wanted me to be. Nobody physically saw me for a year, and that was what I thought they wanted. I had to deconstruct an entire belief system. Toss it out and reject it. It woke me up from constantly feeling like I was fighting for people's respect. It was happiness without anyone else's input. I want to do this. I need to do to be on the right side of history. It feels f***ing awesome.

"I feel really good about not feeling muzzled anymore. And it was my own doing. There's nothing that feels better than this moment."

The documentary, Miss Americana debuts on Netflix on January 31.