All this data is potentially out of date, and should be taken with a truckload of salt
The Takmahl were a race of humans once part of the Amarr Empire. For reasons that remain unknown, but were very likely related at least in part to their Sani Sabik practices, they were exiled from the Empire, and lived for centuries in solitude in the Araz constellation.
Some in the Amarr Empire believe them to be the precursors of the Blood Raiders. They supposedly worshiped different gods and were labeled heretics, which possibly caused their exile, but they were undoubtedly masters of cybernetics and bio-engineering technology.
Their relics and technology can still be found to this day in the Museum Arcana, although the Takmahl themselves are no longer to be found. Their fate is unknown.