Sir Mark Jones has been appointed as interim director of the British Museum by the board of trustees.
Director Hartwig Fischer stepped down from the role after over 2,000 artefacts were stolen from the London museum.
Mr Fischer, a German art historian, said it was "evident that the British Museum did not respond as comprehensively as it should have" in response to "warnings in 2021" about a problem that has now "fully emerged".
"The responsibility for that failure must ultimately rest with the director," he said.
He said the situation was "of the utmost seriousness" and he has "sadly come to the conclusion" that his presence was "proving a distraction".
The institution's chair George Osborne confirmed Sir Jones's appointment of Sir Jones in a statement on Saturday 2 September and said: "Mark is one of the most experienced and respected museum leaders in the world, and he will offer the leadership and grip the museum needs right now.
"We are both clear that his priorities are to accelerate the cataloguing of the collection, improve security, and reinforce pride in the curatorial mission of the museum.
"This sits alongside the major renovation work we're undertaking, and the partnerships we're forging, to ensure that we build a stronger future for the museum we all love and admire.
"I promised we would learn lessons and then lay the foundations for a strong future. Mark's appointment is a big step in that direction. I look forward to working together."
He added that Sir Mark's appointment is subject to Prime Minister Rishi Sunak's approval.
The museum's deputy director, Jonathan Williams, has also "agreed to voluntarily step back from his normal duties".
That will be the case "until the independent review into the thefts at the museum has concluded", the museum said.
Who is Sir Mark Jones?
Sir Jones, 72, is an art historian, who was previously a director at the Victoria and Albert Museum from 2001-2011.
He has also served as an Assistant Keeper of Coins and Medals at the British Museum from 1974 to 1990, and later became Keeper of Coins and Medals until 1992.
He directed the National Museums of Scotland (1992-2001), overseeing the opening of the Museum of Scotland, the creation of the National War Museum of Scotland, and the Museum of Scottish Country Life.
On his first day as director, at the V&A museum, he announced he would be scrapping entry charges to the museum. Under his directorship, a number of renewal projects have been completed, including the Medieval and Renaissance galleries which opened in 2009.
Currently, he holds the position of chair for the Pilgrim Trust, the National Trust for Scotland, and Hospitalfield.