The Umayyad Caliphate (Arabic: الخلافة الأموية‎, trans. Al-Khilāfat al-ʾumawiyya) was the second of the four major Islamic caliphates established after the death of Muhammad. This caliphate was centered on the Umayyad dynasty (Arabic: الأمويون‎, al-ʾUmawiyyūn, or بنو أمية, Banū ʾUmayya, "Sons of Umayya"), hailing from Mecca. The Umayyad family had first come to power under the third caliph, Uthman ibn Affan (r. 644–656), but the Umayyad regime was founded by Muawiya ibn Abi Sufyan, long-time governor of Syria, after the end of the First Muslim Civil War in 661 CE/41 AH. Syria remained the Umayyads' main power base thereafter, and Damascus was their capital. The Umayyads continued the Muslim conquests, incorporating the Caucasus, Transoxiana, Sindh, the Maghreb and the Iberian Peninsula (Al-Andalus) into the Muslim world. At its greatest extent, the Umayyad Caliphate covered 15 million km2 (5.79 million square miles), making it the largest empire (in terms of area - not in terms of population) the world had yet seen, and the fifth largest ever to exist.
How many million square miles was the Umayyad caliphate at its largest size?
5.79

On June 12, 1990, the Congress of People's Deputies adopted the Declaration of State Sovereignty. On June 12, 1991, Boris Yeltsin was elected the first President. On December 8, 1991, heads of Russia, Ukraine and Belarus signed the Belavezha Accords. The agreement declared dissolution of the USSR by its founder states (i.e. denunciation of 1922 Treaty on the Creation of the USSR) and established the CIS. On December 12, the agreement was ratified by the Russian Parliament, therefore Russian SFSR denounced the Treaty on the Creation of the USSR and de facto declared Russia's independence from the USSR.
When did the Russian Parliament ratify the Belavezha Accords?
December 12

Following the death of Grand Prince Igor in 945, his wife Olga ruled as regent in Kiev until their son Sviatoslav reached maturity (ca. 963). His decade-long reign over Rus' was marked by rapid expansion through the conquest of the Khazars of the Pontic steppe and the invasion of the Balkans. By the end of his short life, Sviatoslav carved out for himself the largest state in Europe, eventually moving his capital from Kiev to Pereyaslavets on the Danube in 969. In contrast with his mother's conversion to Christianity, Sviatoslav, like his druzhina, remained a staunch pagan. Due to his abrupt death in an ambush in 972, Sviatoslav's conquests, for the most part, were not consolidated into a functioning empire, while his failure to establish a stable succession led to a fratricidal feud among his sons, which resulted in two of his three sons being killed.
In what year did Sviatoslav take over as leader?
963