Sydney, Sep 28 (PTI): Sydney-based Saudi rights activist who led a campaign for women to drive in the conservative kingdom today vowed to return and become one of the first to legally get behind the wheel.

Manal al-Sharif was imprisoned for nine days after posting a video of herself on YouTube and Facebook driving her car around the eastern city of Khobar in 2011 at the height of the "Women2Drive" protest movement.

She said King Salman's historic decree this week allowing women to drive from next June brought her to tears.

"I can't describe the joy I am feeling. This is a truly historic day," she told The Australian newspaper.

"I'm being honest. I just cried. There had been rumours but you never dare believe them."

Saudi Arabia was the only country in the world to ban women driving, and it was seen globally as a symbol of repression in the Gulf kingdom.

The king's decree is part of an ambitious reform push that runs the risk of a backlash from religious hardliners.

"I'm going back, I'm going to drive -- legally!" said al-Sharif, who came to Australia after she was released from jail for the crime of "driving while female".

"My car is still there, the one I drove. I refused to give it up. My family kept it for me. But I will drive legally this time."

Despite the breakthrough that won plaudits internationally and from inside Saudi Arabia, she refused to take any credit, saying: "No, no, it wasn't me, it was everyone doing everything."

Al-Sharif, 38, has long campaigned for women's rights in Saudi Arabia and this year published a memoir "Daring To Drive", which became a worldwide bestseller.

In an opinion piece for The New York Times in June, she recounted how she narrowly avoided a public whipping for her driving exploits.

"I was threatened -- imams wanted me to be publicly lashed -- and monitored and harassed," she wrote. "I was pushed out of my job. After that, I had to move from my home.

"Without a safe place to work or live, with other Saudis calling for my death, I had no choice but to leave the only country I had ever known."

She added: "I had driven with the hope of freeing women in Saudi society -- and by freeing women, I also hoped to free men."

Saudi Arabia has some of the world's tightest restrictions on women.

Under the country's guardianship system, a male family member -- normally the father, husband or brother -- must grant permission for a woman's study, travel and other activities.

It was unclear whether women would require their guardian's permission to apply for driving licences.