The Irish College of San Jorge at Alcalá de Henares, was founded about 1648, from the estate of Baron George Sylveira (Baron Jorge de la Paz y Silveira), a Portuguese nobleman, related to the McDonnells of Ulster through his mother. After the baron died, his widow Beatriz Silveira implemented his wishes and the College came into existence. Alcalá de Henares is a town to the northeast of Madrid, where the Complutense University was situated. The college and its chapel were dedicated to St. George, and were formally known as the Royal Irish College of St. George the Martyr, Alcala (). Students would study for seven years, Theology and Arts with the college was affiliated to the Complutense University of Madrid (which moved to Madrid, eventually reopening a branch in Alcala as the University of Alcalá), aimed at training clerics for Ireland, Belgium(Flanders) and The Netherlands. The Irish Franciscan Luke Wadding, O.F.M. wrote the statutes for the college.

The first rector of the college was Rev. Godfrey Daniel.

In 1767 following the expulsion of the Jesuits, an attempt was made to merge the Royal Scots College in Madrid with the Irish College at Alcala, and the assets of the Scots college were transferred to the Irish College by Royal decree. This merger was annulled by decree in 1771 and the Royal Scots College re-established at Valladolid.

Colegio Menor de San Patricio or de los Irlandeses (1630-1641)
An earlier college was founded in 1630 by Seán Ó Neill, College of St Patrick in Alacala , after his death in 1641 the college closed due to financial issues. Irish students would have studied at the Studium/University in Alcala before 1630 but were not in a formally in their own college.

Closure
The college like other colleges in Spain was merged into Irish College at Salamanca in 1785. The college archive was transferred to Salamanca, and subsequently as part of the Salamanca Archives in 1951 transferred to St. Patrick's College, Maynooth. In 1796 its church attached to the college was demolished. The building came under the ownership of the Count of Revillagigedo, in 1818, King Ferdinand II, a friend of the Count on a visit to Alcalá de Henares, stayed in the building. In 1936 during the Spanish Civil War in which it lost one of its four bays.

Colegio de los Irlandeses Foundation
In the 1980s the mayor of Alcala oversaw many projects to restore buildings in the city associated with the university, in 1985 restoration work bagan on the Irish College building.
In 1988 as a joint effort of the City Council, the University of Alcalá and the Embassy of Ireland, the Colegio de los Irlandeses Foundation was founded, to maintain the heritage of the college, and to promote educational and cultural  links between the city, university and Ireland. 

In 1996 the University of Alcala took ownership of the building. With funding from the Jefferson Smurfit Group, building was restored and in Agreement with the Irish Embassy and University the building now used to house foreign students. The name of the Plaza de los Irlandeses (Irish Square) is another legacy of the Irish presence in the city.

The connection with Ireland is continued through The Alcalá Centre for Irish Studies (“Alka-Éire”), a research institute at the University of Alcala (Madrid).

Alumni
 Andrew Campbell, Bishop of Kilmore between 1753 – 69
 James Fagan, appointed Bishop of Meath in 1707, but resigned from office (his brother Luke Fagan served Meath and Dublin
 Michael O'Gara, Archbishop of Tuam between 1740 and 1748 (former rector of the college)
 Patrick Tyrrell O.F.M., bishop of Clogher and Meath

Rectors
 Rev. Godfrey Daniel (1648- ) - the first rector
 Rev. John (Juan Malli) Malley 
 Rev. Hugo Fayo
 Rev. Raymond Heneghan (1707-1709)
 Rev. Charles Jordan (1710) and (1712–14)
 Rev. Mathew Talbott (1711–12)
 Rev. James Barry (1714–16)
 Rev. Thomas O'Beime (1716–19) - Bishop of Ardagh (1739-47)
 Rev. John Skerritt (1719–21)
 Rev. James O'Toole (1722–24)
 Rev. Bernard O'Connor (1725–28)
 Rev. Dr Michael O'Gara (1728–40) - Archbishop of Tuam (1740-48)
 Rev. Bemard O'Concannon (1740–42)
 Rev. Dr Gerard Plunkett (1742–44)
 Rev. James (Santiago) Cavanagh (1745–47)
 Rev. Tulio MacKenna (1747–49)
 Rev. Bernard O'Kelly (1748 - interim)
 Rev. James Purcell (1749–52)
 Rev. John O'Lean (1753–54)
 Rev. Bemard Conor (1754–57)
 Rev. William Carington (1758–60)
 Rev. William Murray (1760–61)
 Rev. Patrick Hogan (1761–62)
 Rev. Francis Lonergan (1762–63)
 Rev. John Ward (1763–65)
 Rev. Charles MacDonnell (1765–66)
 Rev. Richard Plunkett (1766–67)
 Rev. James Sheehy (1767–68)
 Rev. Charles (Carlos) MacKiernan (1768–70)
 Rev. Francis (Francisco) O'Lean (1770–71)
 Rev. Patrick Magennis (1773–85) - the final rector

References

Defunct universities and colleges in Spain
Catholic seminaries
Seminaries and theological colleges in Spain
Counter-Reformation
Irish diaspora in Europe
Irish Colleges on the Continent
University of Alcalá