Ages of the actors Richard and Bolingbroke in the time of their production: (this play was produced a lot, couldn't do them all😅)
Richard (Michael Pennington): 48
Bolingbroke (Michael Cronin): 49
Richard (David William): 37
Bolingbroke (Tom Fleming): 36
BBC television shakespeare
Richard (Derek Jacobi): 40
Bolingbroke (Jon Finch): 36
Richard (Mark Rylance): 43
Bolingbroke (Liam Brennan): 39
Richard (Ben Whishaw): 32
Bolingbroke (Rory Kinnear): 34
Bolingbroke (Richard Bremmer): 44
Richard (Ian McKellen): 32
Bolingbroke (Timothy West): 37
Richard (Adjoa Andoh): 56
Bolingbroke (Sarah Niles): 32
Richard (David Tennant): 42
Bolingbroke (Nigel Lindsay): 44
Richard (Charles Edwards): 46
Bolingbroke (David Sturzaker): his age is a mystery apparently, but he's in his 30s-40s now, so in 2015 he was in his 20s-30s. He does not look like a man in his early 20s in the play, but I can't pin down an age.
Youngest: 32 (Ian McKellen & Ben Whishaw) - age accurate
Youngest: (possibly David Sturzaker), 32 (Sarah Niles)- age accurate
Oldest: 49 (Michael Cronin)
It's an even split between productions where Richard is older and ones where Bolingbroke is older.
There are 4 productions with a 4-5 years age difference, 4 where the boys are a year or two apart, none where they are the same age.
The biggest age gap is in the globe 2019 production, with 24 years between our youngest Bolingbroke and oldest Richard. The second biggest age gap is in the 2015 globe, at most 20 years, at least 7.
Excluding the outliers, the average age difference is 3 years, including them, it's 6.
The hollow crown is the closest we have to age accurate casting and age difference.
6/10 Bolingbrokes have a receding hairline, but only 3 are actively balding.