The 3rd Marquess of Bute was a complex man, and the driving force behind the rebuilding of Mount Stuart into the Victorian Gothic masterpiece it is today. He was less than a year old when he became heir to the enormous wealth his father had accrued. After the death of the 2nd Marquess, he would be cared for by his mother, Lady Sophia, but later came under the joint guardianship of Lady Elizabeth Moore and Colonel Charles Stuart upon her own death in 1859. Disagreeing about his upbringing, his guardians fought for custody, and the case was eventually brought before the House of Lords. They decided in favour of Charles Stuart, who became the sole guardian of the 3rd Marquess in 1861.
When he reached his majority the 3rd Marquess controversially converted to Catholicism, a decision which shocked society and inspired Benjamin Disreali's novel Lothair. But on the whole the 3rd Marquess preferred a private life, in which he was able to indulge his various passions and interests: he was a skilled linguist who was conversant in 21 languages, a scholar who held the office of Rector at St Andrews University from 1892 until 1897, and an architectural patron who embarked upon approximately 60 building projects during his lifetime.