Narendra Modi declared a new era in India after his opposition bloc secured the biggest election win in 30 years, with voters tired of sluggish economic growth and corruption handing the Gandhi dynasty a historic defeat.

The Bharatiya Janata Party and its allies won 274 seats, giving the party a majority in the 543-seat parliament, officials results showed Saturday morning in India. Rahul Gandhi, who led the Congress campaign, conceded defeat with his bloc expected to net only 44 seats, the worst ever performance for the party that has governed India for most of the time since independence in 1947. Smaller regional parties were ahead in 145 seats.

“The era of divisive politics is over and it is time for unification,” Modi, 63, told a rally Friday in Gujarat, the western state he’s run since 2001. “I see the dawn of a new era for our country.”

U.S. President Barack Obama phoned Modi to offer his congratulations and invite him to visit Washington.

The results boosted stocks and lifted the rupee as investors bet a stable government would make changes needed to bolster growth in the world’s largest democracy. While Modi’s opponents accused him of inflaming tensions between Hindus and a Muslim minority that stem from the country’s founding in 1947, on the campaign trail he offered a message of economic development.

“It marks the beginning of a new era in Indian politics,” said B.G. Verghese, a visiting professor at the Center for Policy Research in New Delhi and a former aide to late prime minister Indira Gandhi. “This clean break offers a fresh look at basic policies, economic, security, social, and that has to be a good thing.”

Rahul Gandhi, the son, grandson and great grandson of Indian prime ministers, congratulated the new government in brief comments at the Congress party headquarters in New Delhi, saying the BJP and its allies “have been given a mandate by the people of our country.”

“Congress party has done pretty badly,” Gandhi, 43, said as he stood alongside his mother, Sonia Gandhi, the party’s president. “There is a lot for us to think about. And as vice president of the party, I hold myself responsible for what’s happened.”

The BJP scored the biggest victory for a single party since Congress won 404 seats in 1984 in the wake of Indira Gandhi’s assassination. India recorded the highest ever turnout in nine rounds of voting at almost one million polling stations stretching from the Himalayas to tropical islands in the Bay of Bengal.

“This is the first time that BJP has been able to expand it social and geographical boundaries,” Rajnath Singh, the party’s president, told reporters in New Delhi. “The BJP has succeeded in crossing the caste, religion and class divide.”

The best-ever showing for the BJP stems the rise of regional parties over the past three decades as Indians increasingly picked members of their own caste, a millennia-old social hierarchy in India rooted in Hinduism. 

“The mandate signals the maturing of India’s democracy,” said D.G.A. Khan, who teaches political science at the Banaras Hindu University in Uttar Pradesh. “Voters have backed the message of development instead of the caste preferences and parties who have exploited it for years.”

India’s rupee surged past 59 to the U.S. dollar for the first time since July. The S&P BSE Sensex increased 0.9 percent to a record 24,121.74 at the close in Mumbai, after swinging between a gain of 6.15 percent and a loss of 0.1 percent.

“India is back in business,” Andrew Holland, chief executive officer at Mumbai-based Ambit Investment Advisors Pvt., said in an e-mail. “Investors will now watch for the new government’s comments on policy issues such as foreign direct investment and the fiscal deficit to take further decisions, but I don’t see a massive downside.”

The rise of the BJP bloc has come at the expense of the Congress coalition, which has been in power since 2004.

“We never imagined in our wildest dreams that it would be this bad,” Ashwani Kumar, a Congress lawmaker in the upper house of parliament and a former cabinet minister, told CNN-IBN. Ragini Nayak, another party spokesman, said in an interview at party headquarters: “We have conceded defeat with the caveat and reminder that we are not going to give up.”

The economy under Congress had slowed in recent years. Gross domestic product probably grew 4.9 percent in the last financial year, near the decade-low of 4.5 percent in the previous 12 months. Consumer-price gains of 8.59 percent in April were the highest after Pakistan among 18 Asian economies tracked by Bloomberg.

A stable government would open more opportunities for “big-bang” changes, such as passing a goods and services tax, making it easier to acquire land and easing labor rules, according to Sajjid Chinoy, JPMorgan Chase & Co.’s India economist in Mumbai.

“These things are going to take time,” he told Bloomberg TV India. “Turning around the investment environment is not going to be easy. It’s going to be a long, tough slog.”

Modi’s power in parliament won’t be unchecked. While the BJP and its allies will have a majority in the lower house, they have only 61 of the 245 members in the upper house, where seats are distributed based on the strength of parties in state assemblies. The upper house must approve major legislation related to tax, foreign investment and constitutional changes.

Modi, the son of a tea seller, is favored by business leaders because of his record in Gujarat, which has attracted companies such as Tata Motors Ltd. and outpaced the national economic growth rate in 11 of the past 12 financial years for which data is available.