Which handheld system received Pokémon Ruby and Sapphire first?

Pokémon Ruby and Sapphire were first released for the Game Boy Advance.

Developed by Game Freak, the pair launched in Japan on November 21, 2002, as the first main-series Pokémon games for Nintendo's 32-bit handheld. Their improved hardware supported more detailed graphics, new sound capabilities, and larger gameplay systems than the Game Boy Color generation.

Ruby and Sapphire introduced the Hoenn region and 135 new Pokémon. They also added Pokémon Abilities, double battles, Pokémon Contests, and a four-player multiplayer option using compatible link connections.

The games were not direct sequels in story or setting to Gold and Silver, and their original connectivity was limited to other third-generation titles. Remakes called Omega Ruby and Alpha Sapphire later appeared on the Nintendo 3DS in 2014.