On his retirement, Mahathir was named a Grand Commander of the Order of the Defender of the Realm, allowing him to adopt the title of "Tun".
He pledged to leave politics "completely", rejecting an emeritus role in Abdullah's cabinet.
Abdullah immediately made his mark as a quieter and less adversarial premier.
With much stronger religious credentials than Mahathir, he was able to beat back PAS's surge in the 1999 election, and lead the Barisan Nasional in the 2004 election to its biggest win ever, taking 199 of 219 parliamentary seats.

Mahathir was the CEO and Chairman, and hence a senior adviser, to many flagship Malaysian companies such as Proton, Perdana Leadership Foundation and Malaysia's government-owned oil and gas company Petronas.
Mahathir and Abdullah had a major fallout over Proton in 2005.
Proton's chief executive, a Mahathir ally, had been sacked by the company's board.
With Abdullah's blessing, Proton then sold one of its prise assets, the motorcycle company MV Agusta, which was bought on Mahathir's advice.
Mahathir also criticised the awarding of import permits for foreign cars, which he claimed were causing Proton's domestic sales to suffer, and attacked Abdullah for cancelling the construction of a second causeway between Malaysia and Singapore.
Mahathir complained that his views were not getting sufficient airing by the Malaysian press, the freedom of which he had curtailed while prime minister: he had been named one of the "Ten Worst Enemies of the Press" by the Committee to Protect Journalists for his restrictions on newspapers and occasional imprisonment of journalists.
He turned to the blogosphere in response, writing a column for Malaysiakini, an online media news website, and starting his own blog.
He unsuccessfully sought election from his local party division to be a delegate to UMNO's general assembly in 2006, where he planned to initiate a revolt against Abdullah's leadership of the party.
After the 2008 election, in which UMNO lost its two-thirds majority in Parliament, Mahathir resigned from the party.
Abdullah was replaced by his deputy, Najib Razak, in 2009, a move that prompted Mahathir to rejoin the party.

Mahathir continued to attract controversy in retirement for remarks on international affairs.
He is a strident critic of Israel and has been accused of being antisemitic.
In his 1970 book The Malay Dilemma, Mahathir wrote "The Jews are not merely hook-nosed, but understand money instinctively," sentiments he reiterated in a 2018 BBC interview in which he also disputed the number of Jews killed in The Holocaust.
In a 2012 blog post, he echoed past claims by writing that "Jews rule this world by proxy."
Also in 2012 he stated: "I am glad to be labeled antisemitic [...] How can I be otherwise, when the Jews who so often talk of the horrors they suffered during the Holocaust show the same Nazi cruelty and hard-heartedness towards not just their enemies but even towards their allies should any try to stop the senseless killing of their Palestinian enemies."
Mahathir established the Kuala Lumpur Initiative to Criminalise War Forum in an effort to end war globally, as well as the Kuala Lumpur War Crimes Commission to investigate the activities of the United States, Israel and its allies in Iraq, Lebanon and the Palestinian territories.
He has also suggested that the September 11 attacks of 2001 might have been staged by the United States government.

Mahathir underwent a heart bypass operation in 2007, following two heart attacks over the previous two years.
He had undergone the same operation after his heart attack in 1989.
After the 2007 operation, he suffered a chest infection.
He was hospitalised for treatment of another chest infection in 2010.
On his retirement, Mahathir was named a Grand Commander of the Order of the Defender of the Realm, allowing him to adopt the title of "Tun". He pledged to leave politics "completely", rejecting an emeritus role in Abdullah's cabinet. Abdullah immediately made his mark as a quieter and less adversarial premier. With much stronger religious credentials than Mahathir, he was able to beat back PAS's surge in the 1999 election, and lead the Barisan Nasional in the 2004 election to its biggest win ever, taking 199 of 219 parliamentary seats.
Mahathir was the CEO and Chairman, and hence a senior adviser, to many flagship Malaysian companies such as Proton, Perdana Leadership Foundation and Malaysia's government-owned oil and gas company Petronas. Mahathir and Abdullah had a major fallout over Proton in 2005. Proton's chief executive, a Mahathir ally, had been sacked by the company's board. With Abdullah's blessing, Proton then sold one of its prise assets, the motorcycle company MV Agusta, which was bought on Mahathir's advice. Mahathir also criticised the awarding of import permits for foreign cars, which he claimed were causing Proton's domestic sales to suffer, and attacked Abdullah for cancelling the construction of a second causeway between Malaysia and Singapore. Mahathir complained that his views were not getting sufficient airing by the Malaysian press, the freedom of which he had curtailed while prime minister: he had been named one of the "Ten Worst Enemies of the Press" by the Committee to Protect Journalists for his restrictions on newspapers and occasional imprisonment of journalists. He turned to the blogosphere in response, writing a column for Malaysiakini, an online media news website, and starting his own blog. He unsuccessfully sought election from his local party division to be a delegate to UMNO's general assembly in 2006, where he planned to initiate a revolt against Abdullah's leadership of the party. After the 2008 election, in which UMNO lost its two-thirds majority in Parliament, Mahathir resigned from the party. Abdullah was replaced by his deputy, Najib Razak, in 2009, a move that prompted Mahathir to rejoin the party.
Mahathir continued to attract controversy in retirement for remarks on international affairs. He is a strident critic of Israel and has been accused of being antisemitic. In his 1970 book The Malay Dilemma, Mahathir wrote "The Jews are not merely hook-nosed, but understand money instinctively," sentiments he reiterated in a 2018 BBC interview in which he also disputed the number of Jews killed in The Holocaust. In a 2012 blog post, he echoed past claims by writing that "Jews rule this world by proxy." Also in 2012 he stated: "I am glad to be labeled antisemitic [...] How can I be otherwise, when the Jews who so often talk of the horrors they suffered during the Holocaust show the same Nazi cruelty and hard-heartedness towards not just their enemies but even towards their allies should any try to stop the senseless killing of their Palestinian enemies." Mahathir established the Kuala Lumpur Initiative to Criminalise War Forum in an effort to end war globally, as well as the Kuala Lumpur War Crimes Commission to investigate the activities of the United States, Israel and its allies in Iraq, Lebanon and the Palestinian territories. He has also suggested that the September 11 attacks of 2001 might have been staged by the United States government.
Mahathir underwent a heart bypass operation in 2007, following two heart attacks over the previous two years. He had undergone the same operation after his heart attack in 1989. After the 2007 operation, he suffered a chest infection. He was hospitalised for treatment of another chest infection in 2010.
Mahathir Mohamad