Short answers, pulled from the story.
The first record of the name Belograd appeared on the 16th of April 878, in a Papal missive to Bulgarian ruler Boris I. This document marks the earliest known written reference to the city under that specific designation.
Belgrade has been battled over in 115 wars throughout its existence and razed to the ground 44 times during those conflicts. No other European capital shares this specific record of repeated annihilation and destruction.
Today, the population within the administrative area totals 1,682,720 people. This number reflects the density of life packed into a space that has been fought over for millennia.
Sultan Suleiman the Magnificent captured the fort with 250,000 Turkish soldiers and over 100 ships on the 28th of August 1521. Most of the city was razed to the ground, and its entire Orthodox Christian population was deported to Istanbul following this event.
Construction of New Belgrade started in 1948 on the left bank of the Sava river. The new regime rebuilt the city in a modernistic style inspired by Le Corbusier to show progress.