Elon Musk and Grimes have been forced to change their son’s name by law.
Musk and Canadian musician Grimes, born Claire Boucher, began their relationship in 2018, making their public debut at the Met Gala that year.
They share three children: a son born in May 2020; a daughter, Exa Dark Sideræl, born via surrogate in December 2021; and another son, Techno Mechanicus, whose birth date remains private.
Their relationship has been notably ‘very fluid,’ characterized by periods of togetherness and separation, per People.
In September 2021, Musk announced they were ‘semi-separated,’ yet Grimes later referred to him as her ‘boyfriend’ in early 2022.
By March 2022, she confirmed another breakup, though she described Musk as her: “best friend and the love of my life.”
Amid these personal developments, Grimes has publicly distanced herself from Musk’s controversial actions per The Cut, including denouncing fascism following Musk’s Nazi-like salute during a political event in January 2025.
However, a certain law has meant they had to change their firstborn’s name.
The unique name was explained by Grimes in a tweet that broke down the meaning of the different letters.
She shared on social media platforms: “X, the unknown variable, Æ, my elven spelling of Ai (love &/or Artificial intelligence).
“A-12 = precursor to SR-17 (our favorite aircraft). No weapons, no defenses, just speed. Great in battle, but non-violent.”
Grimes and Musk went on to welcome their second child in December 2021 through surrogacy.
The paid named her Exa Dark Sideræl and speaking with Variety, she explained that the name references the supercomputing term exaFLOPS.
She also added that Dark symbolizes ‘the unknown’ and ‘the beautiful mystery of our universe’.
While Sideræl is pronounced ‘sigh-deer-ee-el’ and she claims that it represents ‘the true time of the universe, star time, deep space-time, not our relative earth time’.
Grimes also explained that the name also honors her favorite Lord of the Rings character, Galadriel.
She and Elon Musk welcomed their third child, a son named Techno Mechanicus, who also goes by the nickname \Tau.’
Grimes has not publicly provided further details about the meaning or inspiration behind the name.
The pair welcomed their first child X Æ A-12 in May 2020 and was pronounced ‘Ex Ash A Twelve.’
The imaginative name garnered worldwide attention, with some mocking it while others praised the pair for doing something different.
But, due to Californian law, they were forced to change it since it states that names must be written on birth certificates ‘using the 26 alphabetical letters of the English language’.
Although, apostrophes and dashes can be included in names.
Due to this, Musk and Grimes renamed their son’s name to X Æ A-Xii – replacing the number for the Roman numerals.
Family attorney David Glass explained at the time why the creative, original name would be rejected by the state – despite it being technically legal.
He told People: “In California, you can only use the 26 characters of the English language in your baby name.
“Thus, you can’t have numbers, Roman numerals, accents, umlauts or other symbols or emojis. Although an apostrophe, for a name like ‘O’Connor,’ is acceptable.
“They have an opportunity to appeal the rejection of the birth certificate application but it’s unlikely that it will be granted because, again, California… has been struggling with using symbols.”
