Question: How long did Duke Albert V of Austria reign?
About the article "Austria", section "Middle Ages".

Candidate passages:
  Albert III ("Albrecht III"), duke of Austria until 1395, from 1386 (after the death of Leopold) until 1395 also ruled over the latter's possessions.
Albert IV ("Albrecht IV"), duke of Austria 1395–1404, in conflict with Leopold IV.
Albert V ("Albrecht V"), duke of Austria 1404–1439, Holy Roman Emperor from 1438–1439 as Albert II.
See also below.
Ladislaus Posthumus, son of the above, duke of Austria 1440–1457.  
Albert VI (December 12, 1418 – December 2, 1463), also known as "the Prodigal", from the House of Habsburg was, with his elder brother Emperor Frederick III, an Archduke of Inner Austria (i.e.
the duchies of Styria, Carinthia and Carniola) from 1424 and of Austria from 1457 until his death.
According to tradition, Albert was the exact opposite of Frederick, energetic and inclined to thoughtlessness.
Albert was born in Vienna, the son of Archduke Ernest the Iron of Inner Austria and his wife Cymburgis of Masovia.
After the death of their father in 1424 he and his brother remained under the tutelage of their uncle Duke Frederick IV of the Empty Pockets, who ruled over Further Austria and the County of Tyrol.
Coming of age in 1436 Albert, though a junior heir of Inner Austria, received no full rulership anywhere for a long time, which caused friction in his relations with his elder brother Frederick (Frederick V as Archduke).
When in 1439 both Duke Frederick IV of Further Austria and King Albert II of Germany, Duke of Austria died, Archduke Frederick assumed the guardianship over their minor sons Sigismund and Ladislaus the Posthumous.
As Habsburg patriarch, heir of Inner Austria and regent of Further Austria, Tyrol and the Austria proper, he then ruled over all the dynasty's hereditary lands.
At that stage, Albert began quarreling with his brother and in 1446 claimed the lands of Further Austria from him.
The conflict between the brothers escalated when Duke Ladislaus Posthumous of Austria died childless in 1457 and Frederick, Holy Roman Emperor since 1452, came into his inheritance.
Albert rose up and in 1458 occupied the western part of the Austrian archduchy "above the Enns" (later known as Upper Austria), which he ruled at Linz as a separate principality and, quite small, his portion of Habsburg patrimony.
After laying siege to Frederick in the Vienna Hofburg, he also took over the reign of Austria below the Enns (now Lower Austria) in 1462.
Albert however died childless the next year and all his lands fell back to his elder brother.
In 1452 Albert had married Mathilde ("Mechthild"), daughter of Count Palatine Louis III.
Both are credited for founding the University of Freiburg in 1457. 
 Leopold III, Duke of Austria, Duke of Austria 1365-1379, lost Austria to Albert III.  
Albert the Magnanimous KG (10 August 1397 – 27 October 1439) was King of Hungary and Croatia from 1437 until his death.
He was also King of Bohemia, elected (but never crowned) King of Germany as Albert II, duke of Luxembourg and, as Albert V, archduke of Austria from 1404. 
Albert II of Austria (12 December 1298 – 16 August 1358), known as "the Wise" or "the Lame", was Duke of Austria.