The ICC have formally approved a Test match World Championship and an ODI League, to be introduced after the 2019 ODI World Cup after a landmark day of meetings in Auckland.
While the finer details are still to be confirmed it's understood the first two-year Test championship comprising the game's top-nine teams will commence in 2019, with the top two teams to play in a 'championship' final At Lords in June 2021.
Each national team is required to play in six series over that time, three at home and three away with a minimum of two Tests in that series. It can be expanded to five Tests in a series as well.
The first ODI league will commence in 2020/2021 in the lead up to the 2023 ODI World Cup with the details of that tournament to be confirmed soon.