The Dominus (plural: Domini) series consists of some of the most expensive and coveted hats ever known to the Roblox catalog, even more so than the Domino Crown series, Federation series and the Sparkle Time Fedoras. It and the Kleos series were originally conceptualized by Shedletsky (known as Telamon at the time), and there is also a series of headphones with designs inspired from these hats known as the Musica Dominators.
Traditionally, 26 copies of a limited unique Dominus would be sold for upwards of 10,000 Robux. After the release of the third edition, non-limited Domini and gifts containing them were introduced with the aim of being available to many more users (most of which eventually end up becoming limited).
These hats are heavily desired by many players and are commonly worn as a status symbol by users such as Stickmasterluke. Owning a Dominus in the current day usually signifies that the player is quite wealthy in terms of Robux, and also inspires envy due to their rarity, prices and general aesthetic.
As of November 1, 2019, there are 14 Domini in the catalog as well as various other accessories inspired from them. Only 10 of the 14 Domini (which were all either purchasable for Robux or came out of purchasable gifts) are limited, while the rest are offsale.
'Dominus' is a Latin term which can be used to refer to someone along the lines of a 'master' or 'owner'. It has been used throughout various historical periods to refer to people in power, and is also where the term dominate originates from.
Before the official release of the first Dominus, it could have been previewed on a secret page along with other upcoming hats at that time including the first hat of the Noob Attack series. It was also initially referred to as "Hooded_Valkyrie" (similar to the name of the mesh).
As the first item in the series, Dominus Empyreus was released on January 24, 2010, for 13,337 Robux. Ever since, Roblox has released 1–2 purchasable Domini a year (with the exception of 2017, and 2018).