<human>: Background: Guy Carleton, 1st Baron Dorchester, KB (3 September 1724 - 10 November 1808), known between 1776 and 1786 as Sir Guy Carleton, was an Anglo-Irish soldier and administrator. He twice served as Governor of the Province of Quebec, from 1768 to 1778, concurrently serving as Governor General of British North America in that time, and again from 1785 to 1795. The title Baron Dorchester was created on 21 August 1786. He commanded British troops in the American War of Independence, first leading the defence of Quebec during the 1775 rebel invasion and the 1776 counteroffensive that drove the rebels from the province.
Context: Guy Carleton was born to a Protestant military family that had lived in Ireland since the 17th century, and was one of two brothers (Thomas Carleton) that served in the British military. He also had a sister Connolly Crawford. When he was fourteen his father, Christopher Carleton died, and his mother Catherine Carleton remarried Reverend Thomas Skelton. He received a limited education.  In 1742, at the age of seventeen, Carleton was commissioned as an ensign into the 25th Regiment of Foot, in which in 1745 he was promoted lieutenant. During this period he became a friend of James Wolfe; he may have served with Wolfe at the Battle of Culloden during the Jacobite rising of 1745. Two of his brothers, William and Thomas, also joined the British army.  In 1740 the War of the Austrian Succession broke out in Europe. Despite British troops having been engaged on the European continent since 1742, it was not until 1747 that Carleton and his regiment were despatched to Flanders. They fought the French, but were unable to prevent the Fall of Bergen-op-Zoom, a major Dutch fortress, and the war was brought to a halt by an armistice. In 1748 the Treaty of Aix-la-Chapelle was signed and Carleton returned to Britain. He was frustrated to still only be a lieutenant, and believed his opportunities of advancement would be limited with the end of the war.  In 1751 he joined the 1st Foot Guards and in 1752 was promoted to captain. His career received a major boost when he was chosen, at the suggestion of Wolfe, to act as a guide to the Duke of Richmond during a tour of the battlefields of the recent war. Richmond would become an influential patron to Carleton. CANNOTANSWER
Question: what was his early career?

Answer:
<bot>: at the age of seventeen, Carleton was commissioned as an ensign into the 25th Regiment of Foot,