The 47-year-old -- who guided Ajax to four successive league titles before a disappointing short spell at Serie A giants Inter Milan -- signed a three year contract.

He fills the vacuum left by Sam Allardyce who stepped down at the end of May shortly after steering Palace to safety.

Palace chairman Steve Parish hailed the hiring of de Boer -- who is the only coach in Dutch history to manage a side to four consecutive titles -- as a significant landmark appointment for the London club.

"It's just about the worst kept secret in football," he told a press conference.

"Fantastically exciting for this football club, an amazing milestone for us. I am excited to work with him and what we can achieve with the club."

De Boer is not aiming too high initially. 

"The aim is to be a solid Premier League team, not to struggle with relegation. That is our main target, if we do more that's nice," he said.

He inherits a talented squad but is looking forward to spending in the market to further strengthen it.

French international centre-back Mamadou Sakho could be one of those after impressing during his loan spell from rivals Liverpool last season.

"This club can grow further and further. They spend a lot of money and there is the possibility to do something well with that money," he said.

"I've not met the players yet, we will look at one or two signings but I think it is necessary to see all the players here first."

The 112-times capped De Boer said he had been in touch with Louis van Gaal and got a lot of encouragement from his compatriot.

Van Gaal -- who coached de Boer and the outstanding Ajax side to the 1995 Champions League trophy -- endured a torrid two season spell in charge of Manchester United before being sacked last year.

"I spoke with Louis van Gaal and asked him what the experience was like. He has always been very good to me, he was the first one to congratulate me," De Boer said.

De Boer and his twin brother Ronald were part of a sublimely-talented Dutch side that lost on penalties in the 1998 World Cup semi-finals to Brazil.

He suffered further penalty shootout semi-final heartbreak in Euro 2000 against Italy made worse for him in missing a penalty both in regular playing time and then in the shootout.