Politicians and celebrities have taken to social media to respond to the news of Margaret Thatcher's death as it spread through cyberspace like wildfire this afternoon.
Prime Minister David Cameron used Twitter for his first comment, while politicians and key figures across the globe were among the hordes of people to use the site for their comments and tributes.
The phrases "#MargaretThatcher" and "#Ex-Prime Minister Thatcher" were quickly trending worldwide, with other Thatcher-related phrases quickly gaining their own hashtags.
The world of 24-hour news shifted quickly to the Iron Lady's death, with broadcasters devoting constant coverage to the subject as tributes poured in.
Tory MP Therese Coffey said the former Prime Minister had "transformed" the country, "putting Great back in Great Britain".
And UKIP leader Nigel Farage said she was a "great patriotic lady".
Labour MPs also paid tribute to Baroness Thatcher.
Shadow International Development Secretary Ivan Lewis said: "Hoping all Labour supporters will respond with dignity + respect to news of Baroness Thatcher's death. Our thoughts with her family + friends."
And former Labour minister and MP Tony McNulty tweeted: "God bless her and thoughts are with her family. RIP."
The Liberal Democrat MP Martin Horwood tweeted: "Sad news about Baroness Thatcher. Don't miss her policies but a towering figure in 20th c British politics, & made history UK's 1st woman PM."
Foreign Office Minister Hugo Swire: "Very sad about Margaret Thatcher but what a life. Hugely privileged to have known her."
Conservative backbenchers poured on to Twitter with tributes.
Sarah Wollaston said: "So sad to hear of the death of Baroness Thatcher. An exceptional woman & great Briton. We should be proud of our Iron Lady."
David Burrowes said: "Very sad news of the death of Margaret Thatcher. A truly great PM, transformed Britain holding high the torch of liberty home and abroad."
Chris Heaton-Harris said: "RIP Baroness Thatcher. Few politicians get to win a battle of ideas, let alone inject hope & belief into a nation."
Stephen Mosley said: "Very sad to hear of the death of Baroness Thatcher. An amazing woman who transformed Britain and with Ronald Reagan changed the world."
Former Republican candidate for the US presidency John McCain tweeted: "RIP Margaret Thatcher, one of the great leaders of the 20th century."
Labour deputy leader Harriet Harman said: "RIP Margaret Thatcher, one of the great leaders of the 20th century."
Labour MP for Tottenham David Lammy tweeted: "RIP Margaret Thatcher. Whatever you think of her she will remain a political giant. End of an era."
Communities Secretary Eric Pickles said: "Margaret Thatcher gave this country the confidence to believe in itself. A Great PM."
Former Tory education minister Tim Loughton said: "Like or loathe her Mrs T was a great Briton, a true patriot, a transformational leader, hugely aspirational and undeniably principled.
"No doubt some will dance on her grave but Mrs T was a huge figure in British politics who believed above all in Britain & the little man."
Deputy Commons Speaker Lindsay Hoyle tweeted: "Regardless of any personal opinions, today we can't forget that this marks the passing of a hugely influential figure in British politics."
Labour's Rhondda MP Chris Bryant wrote: "Warm condolences to the extended Thatcher family. A towering figure, who was never afraid of controversy."
Liberal Democrat Greg Mulholland (Leeds North West) said: "I disagreed with Margaret Thatcher, but she was a incredible political figure & the first woman to lead our nation."
Publicist Max Clifford tweeted: "Very sad news about Baroness Thatcher - I didn't agree with her politics or policies, but she was a remarkable lady & a remarkable leader."
Lord Sugar wrote: "Margaret Thatcher died today. A great lady she changed the face of British politics, created opportunity for anyone to succeed in the UK. RIP"
Gay rights activist and campaigner Peter Tatchell wrote: "Margaret Thatcher was an extraordinary woman but mostly for the wrong reasons. Emasculated local government & civil liberties. Section 28"
Nadine Dorries MP tweeted: "Margaret Thatcher enabled my single Mum to buy her council house. The best thing any politician could ever have done for our family."
David Jones MP wrote: "Margaret Thatcher was the greatest Briton of the post-war era. Her contribution to our national life is immeasurable. RIP"
BBC Political Editor Nick Robinson wrote: "The dominant figure of post war British politics is dead. Love her or loathe her Margaret Thatcher shaped this country as few others did."
Welsh First Minister Carwyn Jones "Margaret Thatcher was a major force in British political life who had a significant influence on the landscape of Wales & the UK (1/2). There's no doubt about her personal achievement - as the first woman to become British PM, her place in the history books is assured (2/2)"