|Army List 1787|
If you are researching an officer in the British Army one of the first sources you want to look at is the printed Army List. This is an annual, and sometimes more frequent, publication listing all the officers, arranged by regiment (I should now apologise to military specialists for a gross over-simplification of what the Army List is about, but you know what genealogists are like, we just love lists of names). It is available in major libraries, and some volumes have been published on CD, or are available on commercial websites.
A run of volumes from 1754 to 1879 has now been made available for free download on the Digital Microfilm section of DocumentsOnline, in record series WO 65. There is a separate pdf file for each volume, and they can take a long time to download so you need a good broadband connection. But they are definitely worth the wait; this is not just a scanned version of the printed lists that you may have seen in a library, but the set from the War Office library. Each volume was bound with alternate printed and blank sheets, to allow for hand annotations of commissions, promotions etc during the year.
|Honble Arthur Wesley's first commission|
The example here is a page from the 1787 volume, which shows the very first appearance of the Duke of Wellington in an Army List. He received his first commission as ensign in the 73rd Regiment of Foot on 7 March 1787, and his name is crossed out because in December of the same year he was transferred to the newly-formed 76th Regiment. Before he was created the 1st Duke of Wellington, his name was Arthur Wellesley, but he appears here as the Honble. Arthur Wesley, the original spelling of the name.
I have no family connections in the officer class in the period covered by these lists (my ancestor who fought in the Peninsular War was one of the 'poor bloody infantry'), but I wish I did, because this a great resource.