It was Arthur Shrewsbury of England.
The first batsman to score 10000 runs in Test Cricket was Sunil Gavaskar. He scored 63 in the 4th test against Pakistan in the 1986/87 season to become the first player to score 10000 runs
No one. Highest is 747 by Brendon McCullum
Sunial Gavaskar is the first Indian to score 10000 runs in Test Cricket.