Maximus Brankovitch III is a famous American Quidditch player who played Seeker for the Fitchburg Finches Quidditch team. He was also the Seeker and Team Captain of the United States National Team (QA8).
A talented Seeker who captained the US team in two Quidditch World Cups
Maximus is a Roman family name, which in Latin means "greatest" (Behind the Name).
Brankovitch is a variant spelling of the Serbian surname Branković (Acta Croatica). It means "son of Branko", a given name which is ultimately derived from the Slavic name Bronisław (borna "protection" and slava "glory") (Behind the Name).
From the Web
Writing by J.K. Rowling on Pottermore: History of the Quidditch World Cup
Harry Potter Wiki: Maximus Brankovitch III