William Gilbert Grace was born on 18th July 1848 in Mangotsfield, near Bristol, the son of Dr Henry Mills Grace and his wife Martha (née Pocock). Cricket and medicine were both traditions in the family and his father, uncle and brothers were all cricketers.
In 1863 he played for a local XI against an All-England team and did sufficiently well to be invited to join the All-England team the following year. In 1864 he made his debut for various invitation teams - leading the Gentlemen to victory over the Players at Lord's, for instance. In his career he played both for these invitation sides - including travelling "circus" teams that played for money against local opposition - and for his local county, Gloucestershire. During his career he scored runs far in excess of his contemporaries - in 1871 he became the first player to score 2000 runs in a season, and in 1895 he was the first batsman to reach one hundred centuries. He was also a bowler, taking nearly three thousand first class wickets and far outstripping his nearest rivals. His greatest years were in the 1870s, but he had one final great season in 1895 and played on at the highest level until 1908 - from 1899 onwards, having clashed with the authorities in the Gloucestershire club, for the London County Cricket Club set up by the Crystal Palace Company.
He combined his cricketing career with medicine, entering Bristol medical school in 1867 and completing his studies at St Bartholomew's Hospital, London: in 1879 he finally graduated MRCS (London) and LRCP (Edinburgh). He worked for twenty years in general practice in a working class district of Bristol, and as a doctor for the Bristol Poor Law Union, before winding up his medical practice and moving to London in 1898.
His final game was for his local club, Eltham, in July 1914 (in which, typically, he scored 60 not out). He died of a stroke on 23rd October 1915 at his home in Mottingham, and was buried in Beckenham Cemetary.