For 10 points, name this Austro-Hungarian emperor whose long reign lasted from 1848-1916 and whose nephew was Franz Ferdinand.
This ruler experimented with his country's constitution by drafting the "October Diploma" and the "February Patent," and one incident from the later part of his reign was his veto of the appointment of Cardinal Mariano Rampolla to the Papacy.  His marriage to a woman known as Sisi produced only one heir, (*) Rudolf, who was discovered dead along with his lover Mary Vetsera in the Mayerling Incident.  Succeeded by Charles I, this ruler took the throne after the abdication of his mentally-deficient uncle, Ferdinand I. This man gave up Venetia in Peace of Prague after his forces were defeated at Koniggratz during a war with Prussia.  For 10 points, name this Austro-Hungarian emperor whose long reign lasted from 1848-1916 and whose nephew was Franz Ferdinand.
This ruler experimented with his country's constitution by drafting the "October Diploma" and the "February Patent," and one incident from the later part of his reign was his veto of the appointment of Cardinal Mariano Rampolla to the Papacy.  
{Franz Joseph} I of Austria