The term al-khi
The term al-khilafa al-rashida (the rightly guided caliphate) was coined around or soon after the time of the civil wars that took place between Imam ‘Ali b. Abi Talib and his opponents.
It was designed to contrast the period of the first 3 caliphs, who were promoted as rightly guided, against the rule of 'Ali who was being denigrated by this comparison.
This will probably come as a surprise to our Sunni friends who clearly believe that ‘Ali is very much a part of the rashidun caliphs.