It has proven difficult to trace the ancestry and parentage Eliza Rennie, as no contemporary accounts have been found. The following biography is therefore tentative and incomplete, deduced from a comparison of published local and family histories, clues left by Eliza in her own writings, and a search of parish records and census data. Although
Mary Shelley's biographer,
Emily W. Sunstein, claims that Eliza was born to the famous engineering family Rennie, of
John Rennie the Elder and his sons
George and
John, no corroborating evidence has been found. One possible matching birth record between 1805 and 1820 has been found of an Elizabeth Rennie born on 17 May 1813 to Alexander Rennie and Jean Taylor in the village of
Udny,
Aberdeenshire. Her father was therefore almost certainly Alexander Home Stirling Rennie, born on 13 June 1797 in
Kilsyth, Scotland, a physician who studied medicine at
Marischal College,
Aberdeen, and upon qualification moved to London between about 1818 and 1820. If her mother was the same Jean Taylor born on 8 June 1798 in
Larbert, a few miles from Kilsyth, then Eliza's parents were teenagers when she was born. It is possible that the young couple either
eloped or were sent away to a remote area to avoid the stigma of
illegitimacy. If the above identifications are correct, then Eliza's grandfather was Robert Rennie of Kilsyth (1762–1820), a minister of the
Church of Scotland, author of treatises on the topic of
peat moss, and a contributor to the
Statistical Accounts of Scotland. The family was sufficiently distinguished to be the subject of a page or two in Reverend Anton's
Kilsyth: a parish history. It seems likely from Eliza's
Poems that her mother died when she was very young, though no death record has been traced. She describes a rural childhood with mixed feelings and may have spent some time being cared for by family members in Kilsyth. She was very unhappy, felt betrayed, and apparently moved to London to join her father, possibly following the death of her grandfather in 1824. She spent the rest of her life in London and the
home counties, never losing her
Scottish identity. Her first definite published work was
Poems (1828), released when she was a teenager, possibly as young as thirteen or fourteen. Although it received mixed reviews, it was sufficiently promising to gain her access to
literary salons and the companionship of leading figures of the day. She may have been the lover of Lord
Henry Dillon, one of the early patrons about whom she wrote extensively in
Traits of Character. ==Life with Mary Shelley and her friends==