LARKSWOOD Primary School was re-opened by actor and former pupil Leslie Phillips.
The school in New Road, Chingford, was rebuilt by construction company Kier and funded by money from the Private Finance Initiative between the council, schools and businesses.
Mr Phillips, who starred in two Harry Potter films, Lara Croft: Tomb Raider, three Carry On films and dozens more, cut the ribbon at a packed school assembly.
Speaking to the children, Mr Phillips, 83, who was brought up in Middleton Avenue, Chingford, said: "I am very proud of those kids who come to Larkswood today because it was about 70 years ago I was here."
He told the children about a time he was almost hit with the cane by the then headmaster for allegedly stealing plants.
Mr Phillips said: "Somebody else had taken them and I had found them dumped in the middle of New Road and I was trying to return them.
"The headmaster caught me and asked me: Have you been stealing them?' I was very surprised.
"He went to his office and he got his cane. He did not believe me and asked me to bend over. I was in quite a fright and I ran out of the room and he ran after me with his cane.
"He did catch me but said that because I had made such an effort to escape, he believed me and did not cane me."
Current headteacher David Wright said: "There are three things that happen at school. The first is friends.You always make lots of friends.
"The second is dreams. This is the time to start dreaming about your future. Whatever it is I hope you think back to your days at Larkswood.
"The last is memories. I want you to remember today. The re-opening of this school is something that you will remember for the rest of your life."
Before Mr Phillips re-opened the school, pupils performed a few songs and showcased their talents.
The Phillips family moved to a house worth £325 in Middleton Avenue in 1931 from Tottenham Hale.
The young Leslie went to what is now Larkswood Primary School, New Road, and remembers playing football on the gravel - a much harder surface than today's astroturf.
Mr Phillips remembers doodlebug bombs falling on Chingford during the Second World War.
His brother, Fred, joined the Army to fight.
"As soon as I left school. I was called up. I went home and nobody was there so I wrote a note which said Dear mum, gone to war' and left," said Fred.
During the hostilities he was injured in the Battle of Anzio in 1944. Leslie also fought in the War.
"I wanted to join the Royal Artillery but I was deferred to the infantry and was given three choices of regiment. My first option was the Middlesex Regiment, which was the one Fred was one in.
"I also chose one in Surrey because I wanted to stay in the southbut I was sent to the Durham Light Infantry which showed the authorities did not listen to me."
Leslie and Fred's mother was mugged in Chingford Mount and never recovered from the ordeal.
The actor said she was attacked in the junction of Hall Lane and Chingford Mount Road.
She did not get over the shock and died and his sister also found it difficult to deal with the robbery. She became ill and also died.
Mr Phillips' voice is known by millions as the Sorting Hat, which told the pupils of Hogwarts their various houses, in two of the Harry Potter films and also appeared in three Carry On films.
His catchphrase as a young actor was "Ding, Dong", said is a slow sexy voice, and he rarely appears on a show even today without being asked to repeat it.