The 1707 Acts of Union had merged the Kingdom of England and Kingdom of Scotland into one national entity, but they retained separate legal systems. However, the House of Lords became the highest court of appeal in both English and Scottish law, and as a result, from 1707 Scottish cases on appeal from the Court of Session were sent there. To deal with these cases, a barrister had to be familiar with both Scottish and English law, and Murray found his niche, acting in Scottish cases in the House of Lords as early as 1733. His work in "Moncrieff v Moncrieff" in 1734 established Murray as a brilliant young barrister praised for his performance by Lords Cowper and Parker. After "Moncrieff", Murray was involved in almost every case in the House of Lords, whether it had been appealed from a Scottish court or not.