Prior to his imperial coronation, he was duke of the Inner Austrian lands of Styria, Carinthia and Carniola from 1424, and also acted as regent over the Duchy of Austria from 1439.

During his reign, Frederick concentrated on re-uniting the Habsburg "hereditary lands" of Austria and took a lesser interest in Imperial affairs.

Despite being mocked as "Arch-Sleepyhead of the Holy Roman Empire" (German: Erzschlafmütze) during his lifetime,[2] he is today increasingly seen as an effective ruler.

Historian Thomas A. Brady Jr. credited Frederick with leaving a credible claim on the imperial title and a secure grip on the Austrian lands, now organized as a single state, for his son.

[3] Born at the Tyrolean residence of Innsbruck in 1415, Frederick was the eldest son of the Inner Austrian duke Ernest the Iron, a member of the Leopoldian line of the Habsburg dynasty, and his second wife Cymburgis of Masovia.

Frederick was now the undisputed head of the Habsburg dynasty, though his regency in the lands of the Albertinian Line (Further Austria) was still viewed with suspicion.

On 2 February 1440, the prince-electors convened at Frankfurt and unanimously elected him King of the Romans as Frederick IV; his rule was still based on his hereditary lands of Styria, Carinthia and Carniola, or Inner Austria.

In 1452, at the age of 37, Frederick III travelled to Italy to receive his bride and to be crowned Holy Roman Emperor.

As per tradition, they spent a night outside the walls of Rome before entering the city on 9 March, where Frederick and Pope Nicholas V exchanged friendly greetings.

This coronation took place on the morning of 16 March, in spite of the protests of the Milanese ambassadors, and in the afternoon Frederick and Eleanor were married by the pope.

The Italian humanist Enea Silvio Piccolomini, later Pope Pius II, who at one time worked at Frederick's court, described the Emperor as a person who wanted to conquer the world while remaining seated.

Although this was regarded as a character flaw in older academic research, his delaying tactics are now viewed as a means of coping with political challenges in far-flung territorial possessions.

[7] According to contemporary accounts, Frederick had difficulties developing emotional closeness to other persons, including his children and wife Eleanor.

Despite the fact that their marriage had been unhappy, when Eleanor died the Emperor was affected by her loss and remained widowed for the rest of his long life.

His ascension to the role of Emperor came with the stipulation that should the previous queen of Bohemia (wife of Albert V of the Albertine line) give birth to a male heir, Frederick would become his guardian.

These conflicts forced him into an anachronistic itinerant existence, as he had to move his court between various places through the years, residing in Graz, Linz and Wiener Neustadt.

In 1469 Friedrich founded the Order of St. George, which still exists today, whereby the first investiture in the Lateran Basilica in Rome was carried out by him and Pope Paul II.

[13][14] Mary of Burgundy, sole heir to the rich Burgundian kingdom, after the death of her father Charles the Bold, soon made her choice among the many suitors for her hand by selecting Archduke Maximilian of Austria, the future Holy Roman Emperor Maximilian I (son of Frederick III) who became her co-ruler.

In order to safeguard the peace of the land and against the expansive territorial policy of the House of Wittelsbach, numerous affected empire-related states of Swabia joined in 1488 on Frederick's initiative for the Swabian League.

In some smaller matters, Frederick was quite successful: in 1469 he managed to establish bishoprics in Vienna and Wiener Neustadt, a step that no previous Duke of Austria had been able to achieve.

In 1483 he had to leave his Hofburg residence in Vienna and fled to Wiener Neustadt, where he also was besieged by Matthias' troops for 18 months until the fortress was captured in 1487.

When he attained sole rule after Frederick's death, he would continued this policy of brokerage, acting as the impartial judge between options suggested by the princes.

Austrian historian Adam Wandruszka opines that while he was not an impressive emperor, Frederick III was effective in defending and expanding his family's dynastic interests.

He favoured such Jewish scholars like Jacob ben Jehiel Loans [de], who was the teacher of the Hebraist Johann Reuchlin.

Ursula Schattner-Rieser opines that the foundation of Modern Judaism, arising in the eras of Frederick and Maximilian, was "embedded in the principles of humanism".

In the Lent of 1493, Friedrich's personal physicians diagnosed Kaiser in the left leg as a symptom, usually referred to as age-burning, in the research literature, which according to current medical terminology is considered to be the result of arteriosclerosis.

On 8 June 1493 he was amputated under the direction of the surgeon Hans Seyff in the Linz castle of the affected area of the leg.

His grave, built by Nikolaus Gerhaert von Leyden, in St. Stephen's Cathedral, Vienna, is one of the most important works of sculptural art of the Late Middle Ages.