[2][3] On 29 April 1899, he married Lady Katharine Mary Montagu-Douglas-Scott (a daughter of the 6th Duke of Buccleuch),[3] and they had eight children.

He saw active service in Southern Africa during the Second Boer War from 1899 to 1902, during which he received a brevet promotion to major on 29 November 1900.

[4] He received the substantive rank of major on 14 January 1903,[5] and was later the same year appointed 2nd in command of the 2nd Provisional Regiment of Hussars.

Following the outbreak of the First World War, the Hertfordshires were deployed to the Western Front and Brand remained in command until January 1915.

In 1899, he played in the first international polo match between England and Australia in Melbourne alongside George Bellew-Bryan, 4th Baron Bellew.