Background: Mandaeism or Mandaeanism (Arabic: mndy'y@ Manda'iyah) is a gnostic religion with a strongly dualistic worldview. Its adherents, the Mandaeans, revere Adam, Abel, Seth, Enos, Noah, Shem, Aram, and especially John the Baptist. The Aramaic manda means "knowledge", as does Greek gnosis. According to most scholars, Mandaeaism originated sometime in the first three centuries AD, in Mesopotamia.
Context: As noted above Mandaean theology is not systematic. There is no one single authoritative account of the creation of the cosmos, but rather a series of several accounts. Some scholars, such as Edmondo Lupieri, maintain that comparison of these different accounts may reveal the diverse religious influences upon which the Mandaeans have drawn and the ways in which the Mandaean religion has evolved over time.  In contrast with the religious texts of the western Gnostic sects formerly found in Syria and Egypt, the earliest Mandaean religious texts suggest a more strictly dualistic theology, typical of other Iranian religions such as Zoroastrianism, Zurvanism, Manichaeism, and the teachings of Mazdak. In these texts, instead of a large pleroma, there is a discrete division between light and darkness. The ruler of darkness is called Ptahil (similar to the Gnostic Demiurge), and the originator of the light (i.e. God) is only known as "the great first Life from the worlds of light, the sublime one that stands above all works." When this being emanated, other spiritual beings became increasingly corrupted, and they and their ruler Ptahil created our world. The name Ptahil is suggestive of the Egyptian Ptah--the Mandaeans believe that they were resident in Egypt for a while--joined to the semitic El, meaning "god".  The issue is further complicated by the fact that Ptahil alone does not constitute the demiurge but only fills that role insofar as he is the creator of our world. Rather, Ptahil is the lowest of a group of three "demiurgic" beings, the other two being Yushamin (a.k.a. Joshamin) and Abathur. Abathur's demiurgic role consists of his sitting in judgment upon the souls of mortals. The role of Yushamin, the senior being, is more obscure; wanting to create a world of his own, he was severely punished for opposing the King of Light. The name may derive from Iao has-sammayim (in Hebrew: Yahweh "of the heavens").
Question: Around what time were these theories created?
Answer: 

Background: Led Zeppelin were an English rock band formed in London in 1968. The group consisted of guitarist Jimmy Page, singer Robert Plant, bassist and keyboardist John Paul Jones, and drummer John Bonham. The band's heavy, guitar-driven sound has led them to be cited as one of the progenitors of heavy metal. Their style drew from a wide variety of influences, including blues, psychedelia, and folk music.
Context: In November 1978, the group recorded at Polar Studios in Stockholm, Sweden. The resulting album, In Through the Out Door, featured sonic experimentation that again drew mixed reactions from critics. Nevertheless, the album reached number one in the UK and the US in just its second week of release. With this album's release, Led Zeppelin's entire catalogue returned to the Billboard Top 200 in the weeks of 27 October and 3 November 1979.  In August 1979, after two warm-up shows in Copenhagen, Led Zeppelin headlined two concerts at the Knebworth Music Festival, playing to a crowd of approximately 104,000 on the first night. A brief, low-key European tour was undertaken in June and July 1980, featuring a stripped-down set without the usual lengthy jams and solos. On 27 June, at a show in Nuremberg, Germany, the concert came to an abrupt halt in the middle of the third song, when Bonham collapsed onstage and was rushed to hospital. Speculation in the press suggested that his collapse had been the result of excessive alcohol and drug use, but the band claimed that he had simply overeaten.  A North American tour, the band's first since 1977, was scheduled to commence on 17 October 1980. On 24 September, Bonham was picked up by Led Zeppelin assistant Rex King to attend rehearsals at Bray Studios. During the journey, Bonham asked to stop for breakfast, where he downed four quadruple vodkas (from 16 to 24 US fl oz (470 to 710 ml)), with a ham roll. After taking a bite of the ham roll he said to his assistant, "breakfast". He continued to drink heavily after arriving at the studio. The rehearsals were halted late that evening and the band retired to Page's house--the Old Mill House in Clewer, Windsor.  After midnight, Bonham, who had fallen asleep, was taken to bed and placed on his side. At 1:45 pm the next day, Benji LeFevre (Led Zeppelin's new tour manager) and John Paul Jones found Bonham dead. The cause of death was asphyxiation from vomit; the finding was accidental death. An autopsy found no other recreational drugs in Bonham's body. Although he had recently begun to take Motival (a cocktail of the antipsychotic fluphenazine and the tricyclic antidepressant nortriptyline) to combat his anxiety, it is unclear if these substances interacted with the alcohol in his system. Bonham's remains were cremated and his ashes interred on 12 October 1980, at Rushock parish church, Worcestershire.  The planned North American tour was cancelled, and despite rumours that Cozy Powell, Carmine Appice, Barriemore Barlow, Simon Kirke, or Bev Bevan would join the group as his replacement, the remaining members decided to disband. A 4 December 1980 press statement stated that, "We wish it to be known that the loss of our dear friend, and the deep sense of undivided harmony felt by ourselves and our manager, have led us to decide that we could not continue as we were." The statement was signed simply "Led Zeppelin".
Question: Are there any other interesting aspects about this article?
Answer:
On 24 September, Bonham was picked up by Led Zeppelin assistant Rex King to attend rehearsals at Bray Studios.