The Mangles was built in Bengal in 1803 and weighed 594 tons. This was the first of nine voyages of the Mangles bringing convicts to Australia, the others being in 1822, 1824, 1826, 1828, 1833, 1835, 1837 and 1840
The convicts came from districts throughout England and Scotland - Stockport, Manchester, Derby, Gloucestershire, Woolwich, Inverness, Lancashire, Staffordshire, London, Bristol, Birmingham, Nottingham, Dumfries, Edinburgh and Glasgow. There were also seven prisoners who had been Court-Martialled at Gibraltar, Barbados or Chatham.
Prisoners were admitted to various Hulks to await transportation. - William Webb who was Court-martialled for desertion on 23rd December 1819 and transferred from Chatham Barracks to the Retribution hulk on 23rd February 1820. Three men transferred from Newgate prison to the Bellerophon hulk - John Butler Hewson,Isaac Tillerton and George Williamson had been convicted of forgery with eleven other men at the Old Bailey on 27th October 1819.
Newgate Prison - The Picture of London for 1820
Incidents of forgery were high at this time. In England in the year 1820 a total of 165 people both male and female were sentenced to 14 years transportation for various offences. Of those people 154 had been convicted of forgery or uttering forged bank notes. In 1821, 108 people were sentenced to transportation for 14 years for various offences and of those 86 were convicted of forgery or uttering forged bank notes . In 1822 there were no convictions for those crimes...The Proceedings of the Old Bailey Online page of Currency has the following explanation of the high number of forgeries at this time.....
Between 1797 and 1821, the period known as the estriction, new, primarily copper coins and, most importantly, inexpensively produced £1 and £2 notes were brought into circulation. The poor quality of these notes led to a spate of forgeries, which in turn led to a high number of prosecutions led by the Bank itself, for both forgery and uttering forged notes. An Act was passed in July 1820 for the further prevention of forging and counterfeiting of Bank Notes, the penalty of which was fourteen years transportation.
Surgeon Matthew Anderson
Matthew Anderson kept a Medical Journal from 17 February to 15 August 1820. 
On the 5th March 1820 - The soldiers embarked on board this ship are a detachment of the 48th Regiment and lately marched from Chatham to this place. They are to act as a Guard over Male convicts, about to be embarked for conveyance to New South Wales.
Lieut. Matthews of the 59th regiment., commanded the guard of 30 Privates of the 48th together with another 10 wives and children of the regiment. Michael Bone, age 19, a Private of the 48th was the first mentioned in Matthew Anderson's Medical Journal. He was treated on the day the detachment was embarked for catarrhal and fever. John Adlington of the 48th was treated on 16th March while the ship lay at Sheerness. On 24th March the surgeon inspected the soldiers and found fourteen men were affected with the itch which he attributed to a 'common woman who came on board while the ship was still at Deptford'. Richard Peel of the 48th received the surgeon's attention for fever. 
Many of the prisoners were discharged from the various hulks on the 15th March 1820, however they weren't received on to the Mangles until 17th March...... On the 17th March 1820, 190 male convicts embarked on board ship, and as the weather was severe and cold and their slop clothing (of which appeared to be intended for a warmer climate) was ill calculated to defend their bodies from its effects, many convicts suffered from catarrhal complaints.
Convicts Thomas Rae, described by the surgeon as an elderly, infirm man was treated on the day the prisoners embarked and John King on 28th March at Sheerness. Richard Bushell, James Miller and William Niblett were also treated for illness or injury while still at Sheerness. Several of the elderly and most infirm of the convicts who were much debiliated by the great length of the voyage were supplied from the Hospital stores daily with soup, wine and tea in the evening. 
Passengers included Charles Throsby junior who was a nephew of Charles Throsby of Throsby Park. Charles Throsby junior later married Betsy Broughton (Betsy Broughton narrowly escaped being massacred in New Zealand when the the Boyd was attacked in 1809).
The Mangles departed Falmouth on 11th April 1820. According to Governor Macquarie's Journal the Mangles sailed in company with the Hadlow only parting from her eight days before reaching Port Jackson
The Mangles sailed direct to Port Jackson, arriving on the 7th August 1820, a voyage of 118 days. .
There was a muster held on board where the prisoner's details were recorded. Details such as when and where convicted, sentence, native place, calling, age and physical description were included but not their crimes or where each man was assigned on arrival.
One hundred and eighty-nine prisoners were disembarked in Sydney, one boy being lost on the passage out.
They were inspected by Governor Macquarie in the Jail yard on 15th August 1820 before being distributed throughout the colony.
There were about fifteen boys on the Mangles. A record of their conduct in gaol and the hulks can be found in the Convict Ship Muster Rolls at Ancestry and reveal some interesting assessments.....
George Horton from Worcester was described as having a sly disposition with propensities that render it necessary he should be kept from associating with bad men;
James Robinson was considered stubborn, worthless and incorrigible;
William Long was considered a quiet boy, sent away in consequence of his parents being transported to New South Wales.
Departure from the Colony
The Mangles under Captain Coghill sailed for Calcutta in September. Surgeon Matthew Anderson, Chief Officer Mr. Atherden, Second Officer Mr. Scriff, Third Officer Mr. Brooks.
Notes and Links
1). Find out about bushranger Richard Snead who arrived on the Mangles
2). Matthew Anderson was also employed as surgeon on the convict ships Surry in Surry in 1819, Mangles in 1822 and the Castle Forbes in 1824
6). Convict John Gleeson was assigned to the Lime burners gang after being transported to Newcastle penal settlement for a colonial crime.
7). On 1st December 1821 Governor Brisbane was sworn in as Governor in Chief of the colony. To commemorate this event Pardons were issued by Governor Macquarie to some prisoners. William Belcher who arrived on the Mangles was sentenced to Death for killing his master received a reprieve at this time and was sent to the newly established penal settlement at Port Macquarie instead.
8). Captain John Coghill b.1785 at Wick in Scotland, marr. Jane Grean in 1814. He was Captain and part owner of the Mangles. In 1826 he sold the Mangles and became a settler. After he sold the Mangles he became part owner of Kirkham near Camden and resided there as manager for about ten years. During this time he purchased 5,600 acres near Braidwood where he ran sheep and cattle. In the 1830s he commissioned John Verge to build Bedervale on his property. The house was completed by 1842.
 New South Wales Government. Musters and other papers relating to convict ships. Series CGS 1155, Reels 2417-2428. State Records Authority of New South Wales. Kingswood, New South Wales, Australia (Ancestry)