Killed in action aged 50
No known grave

Thomas Packenham was born in Dublin to the 4th Earl and his wife, Selina Rice-Trevor. He succeeded to the title on the death of his father in 1887.

He was educated at Winchester, and came up to Christ Church in 1881.

In 1887, he was gazetted as a Second Lieutenant in the 2nd Battalion the Life Guards. He served in the Boer War and was wounded.

On November 8th 1899, he married Lady Mary Julia Child Villiers. They had two sons and four daughters.

From 1912, he was Brigadier General commanding the 2nd (South Midland) Brigade of the British 2nd Mounted Division. Initially, based in Egypt, the Division was sent dismounted, to Suvla Bay as reinforcements during the Battle of Sari Bair. On 21 August 1915, the Division was in reserve for the final attack on Scimitar Hill when the initial attack by the 29th Division failed. The yeomanry were ordered to advance in the open across a dry salt lake. Raked by shrapnel fire, most of the brigade halted in the shelter of Green Hill, but Longford led his brigade in a charge which captured the summit of the hill. As he continued to advance, he was killed.

His last words before his death were, reputedly, "Don't bother ducking, the men don't like it and it doesn't do any good...." His body was never recovered as the British made no further advances before the evacuation of Suvla on 20 December.  He is commemorated on a special memorial in Green Hill Cemetery at Suvla.

Of his children, his elder son inherited the title and, dying without children in 1961; his second son, Frank, inherited. A prominent Labour politician, he was made 1st Baron Pakenham in 1945 and married Elizabeth Harman. Three of the 5th Earl’s daughters became writers, one of them marrying the author Anthony Powell.