[not verified in body] Many works in the genre concerto grosso were composed for three solo instruments, including Corelli's concerti grossi, Op.
Antonio Vivaldi wrote several concertos for the same combination of instruments, published for example in L'estro armonico in 1711.
The difference in Corelli's and Vivaldi's approach towards concertos for multiple soloists, as well in style as regarding the name that was used for them, has been explained as relating to differences in music traditions in Rome (where Corelli lived) and Venice (where Vivaldi lived).
This did not prevent that later music historians would often, retro-actively, describe Vivaldi's concertos for multiple instruments as concerti grossi.
Whatever the naming and style differences, both Corelli and Vivaldi set two violins and a cello as the standard group of soloists for triple concertos of the first quarter of the 18th century.