Complex sentence: Tranquilidade (tranquility in english) is a Portuguese insurance company, founded in Oporto in 1871, is a part of a big Portuguese economic group "Grupo Espirito Santo".
Split into simpler sentences: Tranquilidade (tranquility in english) is a Portuguese insurance company, founded in Oporto in 1871. It is part of the Portuguese economic group "Grupo Espirito Santo".