|Country||Ireland / United Kingdom|
|Died||15 September 1835 (aged 37)
London, United Kingdom
|World Champion||1835 (unofficial)|
Early life 
The son of a surgeon, Alexander McDonnell was born in Belfast in 1798. He was trained as a merchant and worked for some time in the West Indies. In 1820 he settled in London, where he became the secretary of the Committee of West Indian Merchants. It was a lucrative post that made him a wealthy man and left him with plenty of time to indulge his passion for chess.
Chess career 
In 1825 he became a pupil of William Lewis, who was then the leading player in Britain. But soon McDonnell had become so good that Lewis, fearing for his reputation, simply refused to play him anymore.
Around 1825-1826, McDonnell played Captain Evans, while the latter was on shore leave in London. McDonnell was beaten with what is now regarded in chess circles as the first creation of the Evans Gambit (1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4).
La Bourdonnais matches 
At that time the world's strongest player was the French aristocrat Louis-Charles Mahé de La Bourdonnais. Between June and October 1834 La Bourdonnais and McDonnell played a series of six matches, a total of eighty-five games, at the Westminster Chess Club in London. McDonnell won the second match (and is thus considered to have briefly been World Champion), while La Bourdonnais won first, third, fourth and fifth. The sixth match was unfinished.
McDonnell was suffering from Bright's disease, a historical classification of nephritis, which affects the kidneys. In the summer of 1835 his condition worsened and he died in London on 15 September 1835 before his match with La Bourdonnais could be resumed.
- Walker, George (1850). Chess and Chess-Players. London: C. J. Skeet.
Notable chess games 
- Louis-Charles Mahé de La Bourdonnais vs Alexander McDonnell, 04, London 1834, Queen's Gambit Accepted: Central Variation. McDonnell Defense (D20), 0-1 The first immortal game of the history of chess, according to Reuben Fine. A purely positional sacrifice of a queen for two minor pieces.
- Louis-Charles Mahé de La Bourdonnais vs Alexander McDonnell, London 1834, Bishop's Opening: Lopez Variation (C23), 0-1 An interesting encounter with chances and errors on both sides, ending with a nice two-knights mate.
- McDonnell versus De La Bourdonnais, Match 4 (16), London 1834 A classic game demonstrating the power of a mobile central block of pawns.
- Alexander McDonnell player profile and games at Chessgames.com
- 1834 Labourdonnais - McDonnell Matches - match scores from Mark Weeks' chess pages
- Edward Winter, Alexander McDonnell (2004)
- Chess and Chess-Players by George Walker