[1] Lennox was a 24 years old lieutenant in the Corps of Royal Engineers, British Army, at the Siege of Sevastopol during the Crimean War, when he was awarded the VC for his: Cool and gallant conduct in establishing a lodgement in Tryon's Rifle Pit, and assisting to repel the assaults of the enemy.

[2]For his Crimea service, Lennox was also mentioned in dispatches and received the Ottoman Order of the Medjidieh (fifth class) and the Sardinian Medal of Military Valor.

[4] Lennox was attached as an observer to the German army during the 1870–71 Franco-Prussian War, and attended Prussian military manoeuvres in 1869 and 1872.

From August 1884 he commanded the garrison at Alexandria, Egypt, and was responsible for landing the troops and stores for the 1884–85 Gordon relief expedition.

He was made a Knight Commander of the Order of the Bath (KCB) in May 1891 and was director-general of military education at the War Office from January 1893 until his retirement in May 1895.

In 2013 the Victoria Cross Trust launched a campaign to raise £25,000 to restore his grave, that had been neglected and was in a state of disrepair.