The first player ever to do this was welsh ledgend Jonhathon Davies.
1993 = Iestyn Harris moved from league to union. In the previous years most players moved from the Union code to league and then back again
It depends, what sort of Rugby do you mean? League or Union?
Depending on the code its either Rugby union which is the 15 player game or Rugby League which is the 113 player game
Are you talking about a player of a certain sports called Sunny? If so I believe you may talking about a rugby player called Sonny Bill Williams: Sonny William 'Sonny Bill' Williams (born 3 August 1985) is a New Zealand rugby union player, heavyweight boxer and former rugby league player. He is only the second person to represent New Zealand in rugby union after first playing for the country in rugby league. In rugby union he usually plays as a centre. He is particularly known in rugby league and rugby union for his ability to offload the ball in the tackle and, in rugby league, for his shoulder charges.
No. Rugby Union = 15 players Rugby League = 13 players
Jason Robinson, winger or fullback both in rugby league and rugby union
England has national teams for both rugby union and rugby league