According to the 1871 census he was born in Burbage and his mother was Hannah GARNER, a single woman.
No birth registration or parish record confirming that she was his birth mother has been identified to date, but in 1861, an H.G. was staying at the Union House in Hinckley with R.G., aged 1.
Hannah was listed as being a nurse on the 1851 Census, so her being destitute with an illegitimate child in 1861 strongly suggests that she was a victim of some unwanted (or at least ill-advised) male attention, possibly from the father of one of her charges.
Hannah's mother had remarried in 1854, and by 1871 Robert was living with his step-grandfather Joseph BRANT, his grandmother Elizabeth BRANT nee ALSOP and his mother.
Personal
Family
World
Date
Age*
Event
Place
c. 1860
0
Burbage, Leicestershire
25 Oct 1884
24
Hinckley, Leicestershire
3 Mar 1885
25
Hinckley, Leicestershire
Q4 1886
26
Hinckley R.D., Leicestershire
Nov 1887
27
Hinckley, Leicestershire
28 Jul 1889
29
St Mary's, Hinckley, Leicestershire, England
Q1 1891
31
Hinckley R.D., Leicestershire
Q4 1892
32
Hinckley R.D., Leicestershire
Q4 1895
35
Hinckley R.D., Leicestershire
Q4 1897
37
Hinckley R.D., Leicestershire
17 Feb 1900
40
Hinckley, Leicestershire
31 Mar 1901
40
Caution: Recorded age does not match calculated age (41).
4 Mill Street, Hinckley, , Leicestershire, England
Occupation: Brick labourer 
Q2 1902
42
Hinckley R.D., Leicestershire
28 Apr 1917
57
Documented age, Calculated age, Estimated age>