This is Joe Root's third consecutive 150+ score. Only seven batsmen have so far found this consistency in Test cricket. Kumar Sangakkara leads the list with four consecutive 150+ scores. However, Root has made all these scores in away tests, which only happened 98 years ago by another Englishman Wally Hammond who did against Australia in 1928/29.
As a captain, only Don Bradman has scored three consecutive 150+ scores back in 1937.