[4] Having joined the Coldstream Guards as an ensign by purchase on 10 April 1810,[5] he arrived in Spain in early 1812 as part of Sir Arthur Wellesley's army.
He fought at the Battle of Salamanca in 1812 and was present at the Siege of Burgos from 19 September to 21 October the same year.
He marched into France in 1813, where he took part in the Battle of Vitoria on 21 June 1813 and the subsequent Siege of San Sebastián from July until September.
[4] Blackman was promoted to lieutenant on 22 January 1814[6] and during the Hundred Days took part in conflicts including the Battle of Quatre Bras on 16 June 1815.
Although the grounds of Château Hougoumont contain a stone marking Blackman's grave, his remains were moved to the Waterloo monument in Brussels Cemetery in 1889.