What was the original name of the Airbus A220 aircraft family?

The Airbus A220 aircraft family was originally called the Bombardier CSeries.

Bombardier developed the CSeries as a family of clean-sheet narrow-body aircraft for the 100- to 150-seat market. The CS100 and CS300 made their first flights in 2013 and entered airline service in 2016 and 2017 respectively.

Airbus acquired a majority stake in the CSeries program in 2018. The CS100 was renamed the A220-100, and the CS300 became the A220-300. The new branding placed the aircraft within Airbus's commercial-product range while preserving its distinct design and Pratt & Whitney geared turbofan engines.

The A220 is therefore not simply a shortened or enlarged A320. It is a separate aircraft family that originated with Bombardier and was later brought into the Airbus portfolio through a strategic partnership and ownership change.