Question: Which of the 140 historical royal ceremonial objects known as The Crown Jewels of the United Kingdom is known as the Sword of Mercy? 

Context articles: Crown Jewels of the United Kingdom
Sword of Saint Wenceslas
Crown Jeweller
Director of the Royal Collection
Curtana
Szczerbiec
Bohemian Crown Jewels
Honours of Scotland
Sword of justice
Master of the Jewel Office

The Crown Jewels of the United Kingdom, originally the Crown Jewels of England, are 140 historic royal ceremonial objects, including the regalia and vestments worn by kings and queens of the UK at their coronations.
The Sword of Saint Wenceslas or the Coronation Sword of Bohemia is a ceremonial sword used in the Kingdom of Bohemia during coronation ceremonies in Prague.
 The blade of the Sword dates back to the 10th century, to the times of St. Wenceslaus.
 Together with the Coronation Cross it is sometimes considered to be a part of the Bohemian Crown Jewels.
 Unlike the proper crown jewels the sword and the cross are permanently displayed as part of the Treasury of St. Vitus Cathedral in the Holy Cross Chapel at the Prague Castle.
The Crown Jeweller is a member of the Royal Household appointed by the British monarch.
 He or she is responsible for the maintenance and, when they leave the Tower of London, security, of the regalia, plate, and fonts which make up the Crown Jewels of the United Kingdom.
 Except for the monarch, only the Crown Jeweller is authorised to handle the Crown Jewels; others may do so with his or her permission.
 The office holder is on call day and night, all year round to attend to the Jewels.
 William Summers, the fifth incumbent (1962–91), said of his job: "Where the Crown goes, there go I".
The Director of the Royal Collection is head of the Royal Collection Department, a department of the Royal Household of the Sovereign of the United Kingdom.
 The department is responsible for the day-to-day management and upkeep of the art collection of the British Royal Family; held in trust for the nation and successive monarchs, it is one of the largest and most important art collections in the world.
 It contains over 7,000 paintings, 40,000 watercolours and drawings, about 150,000 old master prints, as well as historical photographs, tapestries, furniture, ceramics, books, and the Crown Jewels of the United Kingdom.
 The Director of the Royal Collection is also an ex-officio trustee of Historic Royal Palaces.
Curtana, also known as the Sword of Mercy, is a ceremonial sword used at the coronation of British kings and queens.
 One of the Crown Jewels of the United Kingdom, its end is blunt and squared, said to symbolise mercy.
 It is linked to the legendary sword carried by Tristan and Ogier the Dane.
Szczerbiec () is the coronation sword that was used in crowning ceremonies of most Polish monarchs from 1320 to 1764.
 It is currently on display in the treasure vault of the Royal Wawel Castle in Kraków as the only preserved piece of the medieval Polish Crown Jewels.
 The sword is characterized by a hilt decorated with magical formulas, Christian symbols and floral patterns, as well as a narrow slit in the blade which holds a small shield with the coat of arms of Poland.
 Its name, derived from the Polish word "szczerba" meaning a gap, notch or chip, is sometimes rendered into English as "the Notched Sword" or "the Jagged Sword", although its blade has straight and smooth edges.
The Bohemian Crown Jewels, sometimes called the Czech Crown Jewels (Czech: "české korunovační klenoty" ), include the Crown of Saint Wenceslas ("Svatováclavská koruna"), the royal orb and sceptre, the coronation vestments of the Kings of Bohemia, the gold reliquary cross, and St. Wenceslas' sword.
 They were originally held in Prague and Karlštejn Castle, designed in the 14th century by Matthias of Arras.
 Since 1791 they have been stored in St. Vitus Cathedral at Prague Castle.
 Reproductions of the jewels are permanently exhibited in the historical exposition at the former royal palace in the castle.
 The crown was made for the coronation of Charles IV in 1347, making it the fourth oldest in Europe.
The Honours of Scotland, also known as the Scottish Regalia and the Scottish Crown Jewels, dating from the fifteenth and sixteenth centuries, are the oldest surviving set of crown jewels in the British Isles.
 They were used for the coronation of Scottish monarchs from 1543 (Mary I) until 1651 (Charles II).
 Since then, they have been used to represent Royal Assent to legislation in both the Estates of Parliament and the Scottish Parliament, and they have also been used at state occasions including the first visit to Scotland as sovereign by King George IV in 1822 and the first such visit by Queen Elizabeth II in 1953.
A sword of justice is a ceremonial sword used as insignia of a monarch's supreme judicial power.
 In some cases this may have been an executioner's sword that was no longer used for executions, becoming instead a ceremonial one.
 The Crown Jewels of the United Kingdom include two swords of justice: the sharply pointed Sword of Justice to the Temporal and the obliquely pointed Sword of Justice to the Spiritual, whose characteristics are said to indicate that only temporal courts have power over death.
The Master of the Jewel Office was a position in the Royal Households of England, the Kingdom of Great Britain and the United Kingdom.
 The office holder was responsible for running the Jewel House, which houses the Crown Jewels.
 This role has, at various points in history, been called Master or Treasurer of the Jewel House, Master or Keeper of the Crown Jewels, Master or Keeper of the Regalia, and Keeper of the Jewel House.
 In 1967, the role was combined with Resident Governor of the Tower of London.