Simplify the following text for a Grade 6 native English-speaking person.
Original: One of the key decisions Robson made during his brief tenure at Barcelona was the $ 19.5 million signing of Ronaldo , who was influential in a season when Barcelona won the Spanish Cup , Spanish Super Cup and European Cup Winners ' Cup .
Simplified: In the summer of 1996 , Robson became manager at FC Barcelona . In his short time at the club , he signed Ronaldo and led the club to win the Spanish Cup , Spanish Super Cup and European Cup Winners ' Cup .