In 1526, the army of Sultan Suleiman of the Ottoman Empire inflicted a decisive defeat on the Hungarian forces at Mohács. The King of Hungary, Dalmatia and Croatia, Louis II (king 1516-1526), was killed in battle without heir.
The Archduke of Austria, Ferdinand, was elected as successor (King of Hungary 1526 – 1564), while János Szapolyai, who ruled the areas of the kingdom conquered by the Turks as an Ottoman client, contested the Hungarian throne. In 1533, Ferdinand signed a peace treaty with the Ottoman Empire, splitting the Kingdom of Hungary into a Habsburg sector in the west and a sector of John Zápolya (king of Hungary 1526 – 1540) in the east, the latter effectively a vassal state of the Ottoman Empire.
Ottoman Wars (1525–1718) – events
29 August 1526
King Louis II of Hungary leads many of the Magyar nobility
in a headlong rush to destruction by the vastly superior
strength of the invading Ottoman army, led by Sultan
Suleiman I the Magnificent, at Mohács, Hungary; after
Louis's death by drowning in the rout, Hungary loses its
independence until 1918.
27 September 1529
The Ottoman army under Sultan Suleiman I the Magnificent
besieges Vienna, the capital of the Habsburg archduke
Ferdinand I of Austria; the march through flooded Hungary
has taken over two months, allowing Ferdinand to rally
veteran forces into the garrison.
14 October 1529
The Ottoman sultan Suleiman I the Magnificent is forced by
stiff resistance and the onset of autumn to raise the siege of
Vienna, capital of Austria; he retreats with heavy losses.
Despite this, his ally and Archduke Ferdinand I of Austria's
rival for the Hungarian crown, Janos Zápolya, remains in
possession of the Hungarian capital Buda (now Budapest)
and most of the country.
23 July 1532
The need for unity in the face of the Ottoman invasion,
approaching the Austrian capital of Vienna, forces the
Habsburgs to agree secretly the Peace of Nuremberg with the
German Protestants; the Edict of Augsburg outlawing them
is revoked and toleration is agreed until a general council
meets.
7–28 August 1532
The Ottoman invasion of Hungary under Sultan Suleiman I
the Magnificent stalls before the town of Günns
(Burgenland); the stubborn resistance of a small garrison so
delays the Ottoman Turks that the Holy Roman Emperor
Charles V can reinforce the Austrian capital of Vienna in
person, and autumn approaches. The Turks retreat,
devastating Carinthia and Croatia (September).
2 December 1537
An invasion army loyal to Archduke Ferdinand I of Austria,
including German and Bohemian troops as well as Styrian,
Carinthian, and Carniolan levies, is utterly defeated by
Ottoman frontier forces at Valpó.
26 August 1541
The Ottoman sultan Suleiman I the Magnificent, having
invaded Hungary to prevent a Habsburg conquest through
Archduke Ferdinand I of Austria's claim to that kingdom,
takes the capital Buda (now Budapest) and annexes Hungary.
4 September 1543
Ottoman forces under Sultan Suleiman I the Magnificent
assault and take the fortress of Székesfehérvár
(Stuhlweissenberg), Hungary, southwest of Buda (now
Budapest). The sultan returns to Constantinople, having
strengthened the Danube frontier.
25–27 October 1595
The allied forces of Sigismund Báthory and Michael the
Brave, Princes of Transylvania and Wallachia, destroy the
Ottoman army in Wallachia at Giurgiu, on the River Danube,
and expel them from the province. Their Habsburg imperial
allies capture the fortress of Gran (Esztergom) in Hungary.
11 September 1697
Austrian forces under Prince Eugène of Savoy defeat an
Ottoman army under Elmas Mehmed Pasha at Zenta,
effectively ending the Ottoman sultan Mustafa II's campaign
to recover Hungary. Ottoman losses in the battle amount to
nearly 30,000 men.
12 October 1716
Austrian forces under Prince Eugène of Savoy take
Temesvár (now Timisoara, Romania), the fortress that has
resisted Habsburg advances for 164 years in the Banat, the
last Ottoman possession in Hungary.
16 August 1717
The Austrian general Prince Eugène of Savoy defeats an
Ottoman army of 200,000 men under Halil Pasha, at
Peterwardein, Hungary. Halil had been ordered to relieve
Belgrade, on the right bank of the River Danube in Serbia,
which had been under Austrian siege since May. Belgrade
surrenders on 22 August.
21 July 1718
Habsburg Monarchy and the Ottoman Empire. By its terms,
signed through British and Dutch mediation (the eastern
trade of both states had been disrupted by the war), Austria
completes its occupation of Hungary, and gains Belgrade and
a strip of Serbia and Bosnia, the Banat of Temesvár (now
part of Hungary), and Little Wallachia; Venice, in alliance
with Austria since 1716, retains Corfu and its conquests in
Albania and Dalmatia; the Ottoman Empire keeps the Morea
(the Peloponnese) and the island of Aegina, in Greece. The
parties agree to adhere to this agreement for at least 25 years.