A tree on Family Search (but no sources given) gives Robert's father as William Devenport
Birth: 1838 Dublin, Ireland
Death: 1881Warwickshire, England, United Kingdom
(ie he died 10 years before Robert's marriage to Kate Sylvester)
The corresponding GRO death record is
DEVENPORT, WILLIAM HARRIS 42
GRO Reference: 1881 J Quarter in BIRMINGHAM Volume 06D Page 95
Does anybody have his cause of death available ? (he was a miner and was only 42 when he died, possible mining accident that might not be apparent on death cert.)