Question: What actor originally began voicing Shrek before having to be replaced?
About the article "Shrek", section "Abstract".

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Following the success of "Shrek 2", a third and fourth "Shrek" film, along with plans for a final, fifth film, were announced in May 2004 by Jeffrey Katzenberg: ""Shrek 3" and "4" are going to reveal other unanswered questions and, finally, in the last chapter, we will understand how Shrek came to be in that swamp, when we meet him in the first movie."
Katzenberg announced a title for the fourth film in October 2007, "Shrek Goes Fourth", explaining that "Shrek goes out into the world, forth!"
However, in May 2009, DreamWorks Animation retitled the film to "Shrek Forever After", indicating that it would be the last in the "Shrek" series.
In November, Bill Damaschke, head of creative production at DreamWorks Animation, confirmed with "All that was loved about Shrek in the first film is brought to the final film.
"Tim Sullivan was hired to write the script in 2005, but was later replaced by Darren Lemke and Josh Klausner.
Klausner said about the script's evolution: "When I first came onto the project, it wasn't supposed to be the final chapter – there were originally going to be 5 "Shrek" movies.
Then, about a year into the development, Jeffrey Katzenberg decided that the story that we'd come up with was the right way for Shrek's journey to end, which was incredibly flattering."
Mike Mitchell would on board to direct the new installment, shortly before the release of the third film.
There were also rumors in September 2008, while the film was still in pre-production, that Tom Cruise was considered voicing the movie's villain, but these would be later wrecked.
Much of the film was written and recorded in New York City. 
Shrek has steadily grown tired of being a family man and celebrity among the local villagers, leading him to yearn for the days when he felt like a "real ogre".
He takes his family to Far Far Away to celebrate his children's first birthday.
Shrek gets annoyed when the Three Little Pigs eat the kids' cake along with most of the other party food.
A boy named Butterpants (who is said to be a "big fan" of Shrek) demands that Shrek roar.
After he lets out a frustrated roar the entire crowd cheers, reinforcing his belief that no one considers him to be a true ogre.
This coupled with the fact that the birthday cakes were decorated with a "cute" ogre named Sprinkles finally makes Shrek lose his temper, smashes the new cake in front of everyone, and walks out in anger.
He and Fiona argue outside about his reaction which ends with Shrek rashly agreeing that he was happier before he'd rescued her.
After storming off, Shrek encounters Rumpelstiltskin, who had observed Shrek's angry outburst with Fiona, seizes his chance.
He follows Shrek and arranges what appears to be an accident where he is trapped under his carriage.
To "thank" him, he gives Shrek a day to live like a real ogre in exchange for a day from his childhood that he would not remember being erased.
Shrek signs the contract and appears in a reality where he is still feared by villagers.
He takes the opportunity to cause some light hearted mischief until he finds wanted posters for the ogress Fiona and his home deserted and desolate.
He is kidnapped by witches and taken to Rumpelstiltskin, now the King of Far Far Away and possibly Emperor of a good deal more, which has become derelict and run down.
Rumpelstiltskin uses ogres (and some of Shrek's friends) for slavery.
Upon inquiry, Rumpelstiltskin reveals that the day he erased was the day of Shrek's birth.
Therefore, Shrek never saved Fiona, never met Donkey, and consequently Rumpelstiltskin was able to get Harold and Lillian to sign their kingdom away, then cause them to disappear.
When the day ends, Shrek will disappear as well.
Shrek escapes Rumpelstiltskin's castle with Donkey).
Initially terrified of Shrek, Donkey decides to trust him after seeing Shrek cry over his erased history, something he had never seen an ogre do before.
After Shrek explains the situation, Donkey helps him find a loophole: the contract will be nullified if Shrek and Fiona share true love's kiss.
Shrek and Donkey first travel to the dragon's keep where Fiona was kept and find the place deserted and the lava from the crater under the castle has been drained.
They soon encounter a band of ogres who are resisting Rumpelstiltskin.
The ogres are led by a still-cursed Fiona, who after escaping from the tower where she was held captive, keeps the retired and overweight Puss in Boots as a pet.
Shrek does everything he can to gain Fiona's love, but she is too busy preparing an ambush on Rumpelstiltskin.
She is also bitterly cynical and disillusioned about the power of true love and throws herself into planning Rumpelstiltskin's capture.
While sparring with her, Fiona begins to like Shrek, but stops short of kissing him.
Shrek is discouraged, but Puss encourages him to continue pursuing Fiona.
During the ambush, the ogres are captured by the Pied Piper, though Shrek and Fiona managed to escape with the intervention of Puss and Donkey.
Shrek insists Fiona kiss him, saying it will fix everything, but because Fiona does not truly love him it is ineffective.
Upon hearing that Rumpelstiltskin is offering anything desired by the one who captures Shrek, Shrek surrenders himself in exchange for "all ogres" being released.
Fiona remains in custody because, as Rumpelstiltskin points out, she is not "all ogre" (only by night, not by day).
Shrek and Fiona are to be fed to Dragon, but Donkey, Puss and the ogres raid Rumpelstiltskin's castle, allowing Shrek and Fiona to both subdue Dragon and capture Rumpelstiltskin.
As the sun rises, Shrek begins to fade from existence.
But Fiona, having fallen in love with him, kisses him just before he disappears, thereby voiding the contract and restoring Shrek to his world just before he originally lashed out at everyone.
Shrek embraces his friends and family with a newfound appreciation for everything he has, truly living happily forever after. 
Following the success of "Shrek 2" in May 2004, Jeffrey Katzenberg revealed that the "Shrek" story had been outlined into five films almost from the beginning.
"Before the first one was finished we talked about what the whole story of Shrek is, and each of the chapters answers questions about the first movie and gives us an insight," said Katzenberg, ""Shrek 3" and "4" are going to reveal other unanswered questions and, finally, in the last chapter, we will understand how Shrek came to be in that swamp, when we meet him in the first movie."
After the release of "Shrek the Third" in 2007, Katzenberg announced that the fifth film would be released in 2013.
In May 2009, DreamWorks Animation (DWA) announced that the fourth film's title would be "Shrek Forever After", indicating that it would be the last in the "Shrek" series.
Later in 2009, that was confirmed by Bill Damaschke, head of creative production at DWA, with him saying: "All that was loved about Shrek in the first film is brought to the final film.
"Josh Klausner, one of the writers of "Shrek Forever After", explained in 2010 the script's evolution: "When I first came onto the project, it wasn't supposed to be the final chapter — there were originally going to be 5 "Shrek" movies.
Then, about a year into the development, Jeffrey Katzenberg decided that the story that we'd come up with was the right way for Shrek's journey to end.
"In a 2014 interview with Fox Business Network, Katzenberg hinted that the fifth film still may be made.
"We like to let them have a little bit of time to rest," he said of the characters.
"But I think you can be confident that we'll have another chapter in the "Shrek" series.
We're not finished, and more importantly, neither is he."
Following the success of "Shrek 2" in May 2004, Jeffrey Katzenberg revealed that the "Shrek" story had been outlined into five films almost from the beginning.
"Before the first one was finished we talked about what the whole story of Shrek is, and each of the chapters answers questions about the first movie and gives us an insight," said Katzenberg, ""Shrek 3" and "4" are going to reveal other unanswered questions and, finally, in the last chapter, we will understand how Shrek came to be in that swamp, when we meet him in the first movie."
After the release of "Shrek the Third" in 2007, Katzenberg announced that the fifth film would be released in 2013.
In May 2009, DreamWorks Animation (DWA) announced that the fourth film's title would be "Shrek Forever After", indicating that it would be the last in the "Shrek" series.
Later that year, that was confirmed by Bill Damaschke, head of creative production at DWA, with him saying: "All that was loved about Shrek in the first film is brought to the final film.
"Josh Klausner, one of the writers of "Shrek Forever After", explained in 2010 the script's evolution: "When I first came onto the project, it wasn't supposed to be the final chapter — there were originally going to be 5 "Shrek" movies.
Then, about a year into the development, Jeffrey Katzenberg decided that the story that we'd come up with was the right way for Shrek's journey to end..."In a 2014 interview with Fox Business Network, Katzenberg hinted that the fifth film still may be made.
"We like to let them have a little bit of time to rest," he said of the characters.
"But I think you can be confident that we'll have another chapter in the Shrek series.
We're not finished, and more importantly, neither is he."
Fiona appeared in the stage musical version of the 2001 film which debuted in 2008 and closed in 2010.
She was portrayed by Broadway actress Sutton Foster, who earned a Tony nomination for this role.
In the musical, it is revealed that when Fiona was approximately seven years old, she was sent away to her tower to await the noble prince who would rescue her.
Her only company were some old dolls and all she did was re-read fairy tales about princesses in similar situations (Rapunzel, Snow White, etc.)
and learn about proper princess etiquette.
Fiona waited twenty years, growing into a strong-willed, feisty and beautiful young woman and despite becoming more and more impatient (even going so far as to have a fit and rip an entire book right down the middle), she never gave up on the fairy tales.
When Shrek finally arrived to rescue her, she tries to get him to act out the scene she always imagined would happen when her prince would come, though he ends up having to drag her away to escape the Dragon and her skeletons.
Fiona is ecstatic that she is finally free, though confused at first as to why her champion refuses to give her "True Love's First Kiss".
She is shocked and angry when Shrek reveals himself to be an ogre, but runs off to a nearby cave when the sun sets.
During the finale song "Who I'd Be", she overhears Shrek and Donkey's conversation and is moved.
She stands apart from them, alone in the moonlight, in her ogress form.
In Act Two, she wakes up bright and early to greet the day in the show stopper "Morning Person".
Her singing accidentally makes a bluebird explode and she accidentally tosses a deer off a cliff, but when she helps a Pied Piper with his duties, the rats dancing becomes a full-blown tap number, complete with Fiona changing her dress into an attractive dance outfit and leading them.
Shrek and Donkey walk in at the end, astounded by what they have seen.
Fiona apologizes for her behavior, but she and Shrek begin a duel over whose childhood was worse (Here Fiona reveals that she was sent away on Christmas Eve, angering Shrek, who thought he beat her when he said he was kicked out on his seventh birthday).
Upon realizing they were both abandoned at the hands of their parents, they begin a bond, which is sealed in a burping and farting contest between the two of them.
On reaching Duloc, Fiona is reluctant to finally leave her friends and shares one last campfire dinner with Shrek, who mutually doesn't want her to go either.
When the sun sets again, she hides in a nearby barn and Donkey finds her in her ogre form.
She tells him the story of her curse and begs him not to tell Shrek, because she believes nobody could love her when she looks like such a hideous beast.
However, Shrek was outside about to tell her he loved her when he overheard the conversation and thought she was referring to him.
The next morning, Fiona decides to tell Shrek, but he has already brought Lord Farquaad to her.
She is rather unimpressed with his small stature and egotistical attitude, but accepts his proposal and convinces him to move the wedding to before sunset.
In a song originally in the Seattle previews but removed when taken to Broadway, Fiona prepares for her wedding but is unhappy as she has found the fairy tale ending is not really what she wanted.
Before she and Farquaad can share a kiss, Shrek interrupts the wedding and is mocked by Farquaad when he tries to tell her he loves her.
Caught between true love and breaking the spell, Fiona tries to run away but is stopped by a mob of fairy tale creatures that Farquaad had previously banished from the kingdom.
After it is revealed that Farquaad is a "halfling" (half-human/half-dwarf) the sun sets and Fiona transforms amid the confusion.
Shrek, while initially surprised, accepts the change, though Farquaad is furious and banishes her back to her tower when he proclaims himself the new king.
The Dragon crashes through the window, swallows Farquaad, and Shrek and Fiona kiss.
Fiona undergoes a miraculous transformation into...an ogress.
She is surprised that "True Love's Form" isn't as beautiful as she thought it would be, but Shrek still thinks she is beautiful.
Everyone celebrates and lives happily ever after.
Haven Burton, who understudied the role on Broadway, plays her on the North American tour.
Amanda Holden played the role in the West End until she was replaced by Kimberley Walsh.