* 1621 – Cristofano Allori, Italian painter ( b. 1577 )

* 1621 – Guillaume du Vair, French writer ( b. 1556 )

* 1621 – Gerbrand van den Eeckhout, Dutch painter ( d. 1674 )

He was the father of the painter Cristofano Allori ( 1577 – 1621 ).

* 1578 – Philip III of Spain ( d. 1621 )

* 1682 – Avvakum, Russian priest and writer ( b. 1621 )

* 1621 – The Mayflower sets sail from Plymouth, Massachusetts on a return trip to England.

Ambrosius Bosschaert the Elder ( 18 January 1573 – 1621 ) was a still life painter of the Dutch Golden Age.

* 1621 – Roger Boyle, 1st Earl of Orrery, English soldier, statesman, and dramatist ( d. 1679 )

(; 4 October 1542 – 17 September 1621 ) was an Italian Jesuit and a Cardinal of the Catholic Church.

Under Pope Paul V ( reigned 1605 – 1621 ), a major conflict arose between Venice and the Papacy.

* 1621 – Charles d ' Albert, Constable of France ( b. 1578 )

* 1621 – Saint Job of Maniava, Ukrainian Orthodox Saint ( b. 1550 )

* 1621 – Katarina Stenbock, Queen of Gustav I of Sweden ( b. 1535 )

* 1621 – Rebecca Nurse, English colonist executed during Salem witch trials ( d. 1692 )

* 1571 – Michael Praetorius, German composer ( d. 1621 )

* 1621 – Myles Standish is appointed as first commander of Plymouth colony.

* 1621 – Johannes Schefferus, Alsatian humanist ( d. 1679 )

During the 17th century, the French fabulist Jean de La Fontaine ( 1621 – 1695 ) saw the soul of the fable in the moral — a rule of behavior.

* Jean de La Fontaine ( French, 1621 – 95 ).

* 1621-Second battle of Gibraltar on which a Spanish squadron crushed the VOC at the strait of Gibraltar – Battle of Gibraltar ( 1621 )

Galileo initially called his discovery the Cosmica Sidera (" Cosimo's stars "), in honour of Cosimo II de ' Medici ( 1590 – 1621 ).

In his reign ( 1598 – 1621 ) a ten year truce with the Dutch was overshadowed in 1618 by Spain's involvement in the European-wide Thirty Years ' War.

Philip III was succeeded in 1621 by his son Philip IV of Spain ( reigned 1621 – 1665 ).

He received some votes in the 1605 conclaves which elected Pope Leo XI, Pope Paul V, and in 1621 when Pope Gregory XV was elected, but only in the second conclave of 1605 was he papabile.

At an early age, he came to the attention of the papal nephew, Cardinal Scipione Borghese, and in 1621, at the age of only twenty three, he was knighted by Pope Gregory XV.

Pope Gregory XV ( 9 January or 15 January 1554 – 8 July 1623 ), born Alessandro Ludovisi, was pope from 1621, succeeding Pope Paul V on 9 February 1621.

" Gregory secured for the Ludovisi two dukedoms, one for his brother Orazio, made a Nobile Romano and Duke of Fiano Romano, 1621, and the other, the Duchy of Zagarolo, purchased from the Colonna family by his nephew Ludovico Ludovisi in 1622.

Pope Gregory XV ( 1621 – 23 ) sent him as nuncio to the court of the Kingdom of Naples.

* February 9 – Papal Conclave of 1621: Pope Gregory XV succeeds Pope Paul V as the 234th pope.

Paul V died on 28 January 1621 in Rome and was succeeded by Gregory XV.

Also, these two methods tended to produce controversy, and in any case neither had been used for quite some time-the last compromise election was of Pope John XXII in 1316, and the last affirmation ( acclamation ) election was of Pope Gregory XV in 1621.

Adoration was excluded as an election method in 1621 by Pope Gregory XV.

Gregory XV issued two bulls that covered the most minute of details relating to the election ; the first, in 1621, concerned electoral processes, while the other, in 1622, fixed the ceremonies to be observed.

The signature of the elector covered by a folded-over part of the ballot paper was added by Gregory XV in 1621, to prevent anyone from casting the deciding vote for himself.

The reforms of Gregory XV in 1621 and reaffirmed in 1622 created the written detailed step-by-step procedure used in choosing a pope ; a procedure that was essentially the same as that which was used in 2005 to elect Benedict XVI.

" History of the Papacy, Conclaves in the 16th century ; Reforms of Pope Gregory XV, papal bulls: Aeterni Patris ( 1621 ) and Decet Romanum Pontificem ( 1622 )".

With the election of a Bolognese pope ( Gregory XV ) in 1621, Domenichino returned to Rome.

His vanity, avarice, and irascibility soon lost him his English friends ; the projected Spanish marriage of Prince Charles made him anxious about the security of his position in England, and the election of Pope Gregory XV ( 9 February 1621 ) furnished him with an occasion of intimating, through Catholic diplomatists in England, his wish to return to Rome.

* Andrea Baroni Peretti Montalto, announced the election of Pope Gregory XV ( 1621 )

Although he did not get to receive major orders, he was named canon of Santiago in 1617, which was worth the importunations to him of town hall, since he never attended its position ; but he did on the contrary to conclaves who chose the Popes Pope Gregory XV ( 1621 ) and Urban VIII ( 1623 ).

The congregation was made a religious order 18 November 1621 by a Brief of Pope Gregory XV, under the name of Congregatio Clericorum Regularium Pauperum Matris Dei Scholarum Piarum.