Braithwaite (also spelt Brathwaite and other variants) was the author of The History of the Revolution in the Empire of Morocco upon the Death of the late Emperor Muley Ishmael, published in 1729 and translated into Dutch in 1729, German in 1730, and French in 1731.
In his preface Braithwaite describes himself as being in the service of the African Company, and as having, when very young, served in the fleet in Anne's reign, and then having been a lieutenant in the Welsh fusiliers, ensign in the Royal Guards, and secretary to his kinsman Christian Cole, the British resident at Venice, with whom he travelled through Europe.
Thence he crossed to Morocco and joined the British consul-general, John Russel, in his expedition in the emperor's dominions, the experiences of which he relates in his book.
Col John Braithwaite was killed when the vessel "Baltick Merchant" was attacked and captured by a Franco-Spanish privateer (the "Biscaya") off the Scilly Isles.
He was survived by his wife, Silvia (née Cole), his elder daughter Caroline, who married Robert Armitage, his only son Major-General Sir John Braithwaite, 1st Baronet and a younger daughter, Sylvia.