Former Conservative prime minister Sir John Major described Baroness Thatcher as a "true force of nature" and a "political phenomenon".
In government, the UK was turned around under - and in large measure because of - her leadership.
Her reforms of the economy, trades union law, and her recovery of the Falkland Islands elevated her above normal politics, and may not have been achieved under any other leader.
Her outstanding characteristics will always be remembered by those who worked closely with her: courage and determination in politics, and humanity and generosity of spirit in private.
The death of Baroness Thatcher dominates all of the UK newspaper front pages today.
Baroness Thatcher, who was Britain's prime minister for over a decade, has died today aged 87 after suffering a stroke, her family said.