His successor and eldest son Sultan Ibrahim Iskandar married Raja Zarith Sofiah of the Perak Royal Family.

[6] Nevertheless, Sultan Iskandar was reputed to show great concern to his subjects, and was held in high esteem by many of his subjects–particularly the Malays and Orang Aslis.

Sultan Iskandar was notorious for his bad temper which often resulted in violent episodes of rage and brutality to members of his staff and the general public.

[10][11] These claims were made by citing records of notorious incidents,[12] which include an experience of being disinherited from being the Tunku Mahkota of Johor (or Crown Prince in English) by his father, in 1961, as well as a series of alleged criminal acts occurring between the 1970s and the 1990s which were published in the press and provoked widespread moral outrage within the Malaysian public.

[44][45] Since his ascension to the throne, Sultan Iskandar fostered particularly close ties with Singapore, by developing a personal rapport with top Singaporean leaders.

[55] In 2006, they were again seen together in public, after Sultan Hassanal Bolkiah made a state visit to Johor to express his interest in the Iskandar Development Region.

[56] Prior to being the Sultan or Agong, and even during the 1980s and early 1990s, Mahmood's reputation was marred by a number of controversial incidents which received occasional attention from the media.

[25] However, some eyewitnesses challenged the legitimacy of Mahmood's reappointment as the Mahkota, by arguing that they witnessed Sultan Ismail already having lapsed into coma at the time of his appointment as the regent.

[66][67][68] Similarly, his eldest son, Tunku Ibrahim Ismail, was convicted in the 1980s for shooting a man to death in a nightclub during a feud, but was quickly pardoned.

The brother of the caddy – who also suffered injuries during the incident, being distressed from what he saw, subsequently ran amok in Kuala Lumpur and had to be quarantined in a mental hospital.

[71][72] In late 1992, two separate assault cases by the Sultan as well as his younger son, Tunku Abdul Majid Idris, on hockey coaches culminated in the stripping of immunity of rulers from prosecution.

[76] The incident resulted in the Malaysian Hockey Federation issuing Majid — then second-in line to the throne after his elder brother — a ban of five years from participating in any tournaments following investigations.

[77] Tunku Abdul Majid was later convicted of assault in January 1993, of which the chief justice sentenced him to a year in prison, on top of a RM 2,000 fine.

[78] The Sultan responded to the ban by putting pressure on the state authorities to pull Johorean hockey teams from all national tournaments.

[83] A good deal of these alleged misdeeds that were mentioned included the charging of exorbitant fines–way above the prescribed legal limits–upon offenders who had obstructed the Sultan's car, amongst others.

The bill, which proposed to strip rulers and members of the royal families of legal immunity, would make them prosecutable by the law in any cases of proven criminal wrongdoings.

[92] Sultan Iskandar organised a rally which was to be held outside the palace with the aim of garnering public support to stall the bill's implementation.

A report made during the rally quoted Sultan Iskandar calling upon all local civil servants to boycott state and federal functions in a show of support for his motion.

[96] Sultan Iskandar and his family members were not prosecuted for their past violations of the law on grounds that the royal immunity was still applicable when those incidents occurred.

In a public speech shortly after the episode, the Sultan was noted to have somewhat toned down his hardline image and appeared to be somewhat more humble, appealing to Johoreans to maintain their loyalty to him.

The Sultan reportedly fostered close relations with several key military personnel, including the Army chief Jeneral Zain Hashim.

[105] However, observers suggested a remarkably warm relationship[71] between Prime Minister Mahathir Mohamad and the Agong, both of whom shared common resentment towards the chief justice, Salleh Abas.

As the public prosecutor, Salleh had appealed to the chief justice, Raja Azlan Shah, for handing down a heavier sentence for Iskandar, which earned his wrath.

[111] Earlier sources however, noted Sultan Iskandar's concerns with the deepening rift between Mahathir and Abdullah and had asked to be photographed together with the two leaders during the United Malays National Organisations (UMNO) 60th anniversary celebrations in Johor Bahru.

[115] Gwee, a Democratic Action Party (DAP) ADUN, reportedly argued that there was no stated order to wear the official attire and songkok and stated his desire to wear a western suit,[116] promptly drew flak from other ADUNs and the Menteri Besar, Abdul Ghani Othman who had earlier on met to agree to don in the official attire and songkok prior to the assembly, whereby Gwee was absent.

These documentaries drew criticisms from the Malaysian public, who felt that the television clips of Sultan Iskandar were inappropriate for its theme and national image.

[121] In 1956, Mahmood married Josephine Ruby Trevorrow, from Cornwall, United Kingdom, with whom he had four children, including his successor, Sultan Ibrahim Iskandar of Johor, King of Malaysia (as of 31 January 2024), and Tunku Azizah Aminah Maimunah Iskandariah.

[59] Analysts such as Kate Wharton have observed that any literal references to Trevorrow's association with Sultan Iskandar were carefully omitted in all official biographies.

After undergoing a coronary bypass operation in the United States in 2000, close aides reported that Sultan Iskandar slowed down somewhat in his pace of life and took to playing golf only on an occasional basis.

[127] Sultan Iskandar died on 22 January 2010 at 7:15 pm at the Puteri Specialist Hospital, Johor Bahru after being admitted earlier in the day following an illness at age 77.