He was commander of the Cambrian Rangers a fencible regiment stationed in Gibraltar in 1801[1] He succeeded his father as second Baron Kensington in 1801 but as this was an Irish peerage it did not entitle him to an automatic seat in the House of Lords.

Haverfordwest was considered a pocket borough of the Picton Castle estate and both Kensington and his father held the seat as part of an arrangement with Lord Milford, the owner of the estate and Lord Lieutenant of Pembrokeshire.

He died in August 1852, aged 75, and Edwardes Square, London W8 is named in his honour.

London and Edinburgh Gazette entries record his early career: he joined the 17th Dragoons as a Cornet by purchase in 1824, transferred to be a Cornet and Sub-Lieutenant in 2nd Life Guards in the same year, and had risen to captain in 32nd Foot by 1828.

[6] He was a "bitter enemy of the Brookes...deeply jealous of Sarawak" (the adjacent British-ruled, albeit independent, power).,[7] which led to his being relieved of his position as Consul-General to Brunei, and his Governorship terminated, in 1861 after he had incurred British government displeasure for his use of the HEIC steamer Victoria to travel to Muka and threaten to fire a broadside at Sarawak forces unless they ceased their activities against Sherip Masahor.