Sebastião de Arriaga

Sebastião José de Arriaga Brum da Silveira (1774–1826) was a Portuguese military commander.

Early career
Arriaga enlisted at the age of nineteen as an ensign in the Infantry company of Fortaleza de Santa Cruz, Faial Island, in The Azores, later transferring to Artillery.

Peninsular War
As a captain, Arriaga commanded one of the two batteries brigaded under Major Alexander Dickson that accompanied Beresford's Army to Estremadura, and saw action at the Battle of Albuera (16 May 1811). The following September–October, his company was one of the two Portuguese Artillery companies that formed part of Hill's forces, together with Lefebure's R.H.A. Troop, Hawker's and Meadows's Royal Artillery Companies.

Major Arriaga's 24-pounder howitzer battery, belonging to the 1st (Lisbon) Regiment, formed part of the Artillery Reserve, and accompanied Wellington's own army to the siege of Badajoz (16 March – 6 April 1812), Salamanca (22 July 1812), and the siege of Burgos (19 September – 21 October 1812).

Arriaga's Portuguese artillery company, together with Glubb's British company, and who brought with them six 24-pounder howitzers, a pontoon train, and wagons carrying some 30-foot ladders for escalading work, were attached to Dickson's detachment for the raid at Battle of Almaraz (May 1812).

Arriaga's artillery company formed part of the reserve at the Battle of Salamanca (22 July 1812).

For his action at the Battle of Vitoria (21 June 1813), Major Arriaga, commanding the 1st Artillery Brigade, was mentioned in dispatches by the Commander of the Portuguese Artillery, Lieutenant colonel Dickson, Wellington's "most trusted artillery officer", for making "good and accurate fire" and averaging fifteen shots per gun.

Arriaga's 1st Brigade took part in the Siege of San Sebastián (7 July – 8 September 1813) as part of Dickson's siege artillery, and was again mentioned in dispatches by Dickson.

Arriaga later saw action the Battles of the Nive (9–13 December 1813 and was again mentioned in dispatches by Dickson.

Now a lieutenant colonel, Arriaga served under Lieutenant colonel Victor von Arentschild, commander of the Artillery Brigades, at the Battle of Toulouse (1814).

Post-war period
From 1815 to 1821, Arriaga was the military governor of São Miguel Island and later, as a brigadier, and until his death, the governor of the Fort of São Julião da Barra.