Speaking at a service in the House of Commons Members' Lobby, Prime Minister David Cameron said: "History has been kind to Winston Churchill. Not because he wrote it but because he shaped it.
"He left a Britain more free, more secure, more brave and more proud. And for that we always be grateful to him."
Meanwhile, the boat that carried Sir Winston Churchill's coffin down the River Thames made the same journey this lunchtime.
Relatives travelled on board in remembrance of the man who led Britain to victory in World War Two.
A service of remembrance is also taking place at Westminster Abbey on Friday evening.
Fifty years ago thousands took to the streets to pay tribute to the 90 year old who died after suffering a severe stroke.
One of those who gathered in Westminster was former Cabinet Minister and Christian, Jonathan Aitken.
He told Premier: "The atmosphere at that time was one of mourning but mourning not so much for a 90 year old man who died in the fullness of years, but mourning for the passing of an era.
"Churchill represented so much that was British history in the 20th century in particular his amazing leadership during World War Two.
"We remember him partly for his sheer historical achievements...but also for the qualities he embodied."
Listen to Jonathan Aitken speaking about Sir Winston Churchill with Premier's Marcus Jones: