RIYADH, Saudi Arabia — Saudi Arabia’s surprise decision to grant women the right to drive rattled society in the kingdom on Wednesday, bringing cheers from rights activists and young people and grumbling from others who say they will never let their wives and daughters behind the wheel.

It also demonstrated how the power of ultraconservatives to impose their will has weakened as the kingdom’s 32-year-old crown prince steams ahead with sensitive reforms under his father, King Salman.

The lifting of the ban is the most dramatic step yet in a campaign by Crown Prince Mohammed bin Salman to modernize the kingdom. The young royal has been promoting change to boost the country’s economy and ease international criticism, all while risking backlash from clerics and others who adhere to the ultraconservative Wahhabi interpretation of Islam.

After muscling his way into de facto power, the crown prince appears to have no immediate rivals within the royal family — and at such a young age could hold authority for decades. His ability to ram through reforms suggests conservatives, even if they represent a significant portion of the population, are unwilling to defy the crown prince and king and unable to shore up opposition from other royals and within society.

In 1990, during the first driving campaign by activists, women who got behind the wheels of their cars in the capital, Riyadh, lost their jobs, faced severe stigmatization, and were barred from travel abroad for a year.

‘‘It’s been 27 years of demanding and asking, but a whole lifetime of suffering,’’ said Dalal Kaaki, who joined the protest movement years later. ‘‘I can’t really celebrate because every time I come to celebrate I remember all the years of suffocation. . . . Of trying to arrange transportation to work and having to beg people at home to take me to run errands.’’

‘‘I’m feeling a mix of joy and disbelief, but I’m also grateful that my grandchildren won’t have to go through what I went through,’’ she said.

The move was praised by world leaders. The White House said President Trump views the change as ‘‘a positive step toward promoting the rights and opportunities of women in Saudi Arabia.’’

The decision to allow women to drive may have taken decades of struggle, but it also came swiftly and as a surprise.

Just three years ago, two Saudi women were detained for more than two months for defying the ban on driving. Others were detained over the years during various efforts by women’s rights activists to drive. Often, police would detain a female driver until a male relative could pick her up and sign a pledge on her behalf that she would not drive again.

In some instances, women had their cars confiscated for months. In 2011, at the height of the Arab Spring protests, a Saudi woman was sentenced to 10 lashes for driving, although the Saudi king at the time overturned the sentence.

Under the new guidelines, all Saudi women will be allowed to drive by next summer and they will not require the permission of a male relative to obtain a driver’s license.

Saudi Arabia was the only country in the world still barring women from driving as their counterparts in other Muslim countries drove freely.

Sahar Nasief, who lives in the Red Sea city of Jiddah, was actively campaigning for women to drive. She could drive in the United States, Egypt, and neighboring Dubai on visits, but not in her own country. She said she couldn’t believe the news when her son called to tell her.

‘‘Things have to change. People are demanding it,’’ she said. ‘‘Young people don’t want to live the way we lived. They want to live better. They want to live how other people are living.’’

Saudi Arabia’s crown prince is set to inherit a country where more than half the population is under 25 years old and 70 percent are under 35. Millions are active users of social media, where criticism of the government is rife.