Complex sentence: The airline was established on 18 May 1988 as TEA Basel and started operations on 23 March 1989 as part of the TEA group of airlines which provided charter flights from various European destinations.
Split into simpler sentences: The airline was established on 18 May 1988 and started operations on 23 March 1989. It was originally known as TEA Basel and was founded as part of the TEA group of airlines which provided charter flights from various European destinations.