Her spokesman Lord Bell revealed the news that the former politician had passed away after a long battle with poor health.
Lord Bell said:
'It is with great sadness that Mark and Carol Thatcher announced that their mother Baroness Thatcher died peacefully following a stroke this morning.
'A further statement will be made later.'
The former leader of the conservative party who won three consecutive general elections, has been in fragile health since she suffered a series of minor strokes more than a decade ago.
She was called the "Iron Lady" for her personal and political toughness.