He was born in
Colchester, the son of a barrister, the
Jamaica born
Robert Charles Dallas (1754–1824), who wrote a history of the
Second Maroon War. His grandfather, Dr. Robert Charles Dallas (1710–1769), was a doctor who amassed a fortune in Jamaica. Dr. Dallas bought the Boar Castle estate on the
Cane River, Jamaica in 1758, changing its name to Dallas Castle. He left the island in 1764, having mortgaged the estate and put it in a trust. This property included 900 acres and 91 slaves. Dallas was educated at home to age 11, and then at a school in
Kennington. Through his father, he became a clerk in the Treasury, in 1805. He went on to be a supplies officer during the
Peninsular War. He was present at the
Battle of Waterloo in 1815. Dallas married in 1818. He entered the
Middle Temple to study law in 1819. He left soon, and in 1820 matriculated at
Worcester College, Oxford, at age 28. There he encountered evangelicals, and did not complete a degree. He was ordained a deacon and then a priest in the
Church of England in 1821, and became curate of
Radley. ==Missionary Work==