Two channels having been made through the sunk vessels with which the Spaniards had blocked up the entrance of the harbour, the troops and artillery were re-embarked, and commenced landing on the 5th of April near the city. The country round Carthagena was found covered with trees and herbage of the most luxuriant growth, and the interwoven branches formed a shelter impenetrable both to heat and light; as the troops, led by Brigadier-General Blakeney, advanced along a narrow defile, several men were wounded by shots from the openings into the wood; on diverging from the defile six hundred Spaniards were seen advantageously posted to dispute the passage; but they were speedily driven from their ground, and the British bivouacked within a mile of the castle of _Lazar_, which commanded the town. The men passed three nights in the open air for want of tents and tools, which could not be landed sooner, and the health of the soldiers was in consequence seriously injured. The siege of the castle was commenced, but as the men were fast diminishing in numbers from hard duty and the effects of climate, Brigadier-General Wentworth resolved to attack _St. Lazar_ by escalade. The attempt was made on the 9th of April before day-break, but without success, although the assailants evinced distinguished gallantry. After sustaining a most destructive fire for several hours with intrepidity and perseverance, the troops were ordered to retire, having sustained a severe loss in killed and wounded. Violent periodical rains commenced, the country was deluged with water, and the change of atmosphere produced fatal effects on the health of the men, who were drenched with rain. All hope of further success immediately vanished, and the troops returned on board the fleet, where numbers died from the distempers incidental to the climate. The forts of the harbour of Carthagena having been demolished, the fleet sailed for Jamaica, and the portion of the THIRTY-SIXTH regiment which had formed part of the expedition subsequently returned to Great Britain. [Sidenote: 1743.] During the year 1743 the THIRTY-SIXTH regiment was stationed in Great Britain. [Sidenote: 1744.] In the year 1744 France and Great Britain, from being auxiliaries in the “_War of the Austrian Succession_,”[7] became principals in the contest. On the 20th of March 1744 France declared war against England, and on the 29th of that month a counter-declaration was made by Great Britain, in which the French Monarch was accused of violating the “_Pragmatic Sanction_,”[8] and of assisting the son of the Pretender in his designs on the British throne. In the spring of 1744 the THIRTY-SIXTH and other regiments were embarked to join the troops in Flanders; but the operations of the British army during that year were confined to the defensive, and no general engagement occurred. [Sidenote: 1745.]