Vatican City is not called the Holy See. Vatican City is the home and headquarters for the Holy See - the governance of the Catholic Church. The name derives from the Latin Sancta Sedes - Holy Seat and is the ecclesiastical jurisdiction of the Catholic Church in Rome, the episcopal see of the Bishop of Rome—the Pope.
There are several reasons for this but the main goal was to conquer Jerusalem, the holy city and to expand the power of the holy catholic church.
.Catholic AnswerVatican City is a sovereign city-state wholly owned by the Catholic Church with the Holy Father as its sovereign.
Vatican City, home of the Pope and religious center of the Roman Catholic church, is considered to be the "holy land" located in Rome.
Holy Spirit Catholic School was created in 1963.
Holy Angels Catholic Academy was created in 1924.
Holy Cross Catholic Academy was created in 1986.
Holy Child Catholic School was created in 1945.
Because it is where St. Peter and his successors the Popes set up the headquarters of the Catholic Church.
Rome. That is where Peter first built the church. Today its known as the Vatican.Roman Catholic AnswerMany cities are known as Holy, but the primary one for Christians, as well as Jews, is Jerusalem. But the Catholic Church is in all cities in the world, although not openly in some Muslim nations.
.Catholic AnswerThe Catholic Church is centered in Our Blessed Lord, Jesus Christ. He resides physically on earth in the Blessed Eucharist which is at the heart of every Catholic Church, its "center", if you will. His Vicar on earth is the Holy Father, who resides in the Vatican, an city-state within the city of Rome, Italy.
If by "Catholic holy book" you mean the Catholic version of the bible, then the answer is anyone who feels like picking up a copy.