The 10-year-old John would have been the next king according to the line of succession.
He was also the first person in the line of succession.
"But I still asked them what place they had in the line of succession."
Actually, the first problem was the issue of his succession.
At present, there are no others in the line of succession.
At least in public, there is no talk of succession.
That, in any case, was expected to be the line of succession.
The most recent law about the line of succession was passed in 1947.
Not that the subject of succession hasn't come up since 1947.