I think Phillippe the Fair(Phillippe IV) was an extremely succesfull medieval ruler.
I don't know if he was the greatets, but the man really made some amazing accomplishments:
1- Unifying the currency(against the interests of the barons)
2- Defeating Flanders in severall ocasions and making it part of France.
3-Peacefully managing to unite the crown of Navarra with the french one.
4- Making the English king Edward II to pay him tribute
5- Destroying the Templars, who were so powefull that threatned the king's authority, and taking all of their possessions to the state
6-Making the Church move to Avignon, and to be under the complete controll of himself.
I don't know if he was the greatets, but the man really made some amazing accomplishments:
1- Unifying the currency(against the interests of the barons)
2- Defeating Flanders in severall ocasions and making it part of France.
3-Peacefully managing to unite the crown of Navarra with the french one.
4- Making the English king Edward II to pay him tribute
5- Destroying the Templars, who were so powefull that threatned the king's authority, and taking all of their possessions to the state
6-Making the Church move to Avignon, and to be under the complete controll of himself.