Which Assassin's Creed game introduced the modern-day character Layla Hassan?

Assassin's Creed Origins introduced the modern-day character Layla Hassan.

Layla is an Abstergo Industries researcher who becomes the modern-day protagonist of Origins. She uses a portable Animus to explore the memories of Bayek of Siwa, a Medjay living in Ptolemaic Egypt. Her storyline connects the ancient setting to the series' continuing present-day conflict.

Origins was released in 2017 and marked a major redesign of the series, emphasizing role-playing systems, open-world exploration, equipment, and character progression. Layla's introduction also shifted the modern-day narrative away from the earlier central focus on Desmond Miles.

A common mix-up is to identify Layla with Kassandra or Alexios, the playable figures in Odyssey. Those characters belong to the ancient Greek storyline, while Layla remains the modern-day character who investigates historical memories through the Animus.