Janusz Radziwiłł (2 July 1579 – 3 December 1620) was a noble and magnate

Szlachta

The szlachta was a legally privileged noble class with origins in the Kingdom of Poland. It gained considerable institutional privileges during the 1333-1370 reign of Casimir the Great. In 1413, following a series of tentative personal unions between the Grand Duchy of Lithuania and the Kingdom of...

 of the Polish–Lithuanian Commonwealth. He was the podczaszy

Podczaszy

Podczaszy was since the 13th century a court office in Poland and later in Lithuania. Podczaszy was the deputy of Cześnik, with the time more important than his superior....

 of Lithuania

Grand Duchy of Lithuania

The Grand Duchy of Lithuania was a European state from the 12th /13th century until 1569 and then as a constituent part of Polish-Lithuanian Commonwealth until 1791 when Constitution of May 3, 1791 abolished it in favor of unitary state. It was founded by the Lithuanians, one of the polytheistic...

 since 1599, the castellan

Castellan

A castellan was the governor or captain of a castle. The word stems from the Latin Castellanus, derived from castellum "castle". Also known as a constable.-Duties:...

 of Vilnius

Vilnius

Vilnius is the capital of Lithuania, and its largest city, with a population of 560,190 as of 2010. It is the seat of the Vilnius city municipality and of the Vilnius district municipality. It is also the capital of Vilnius County...

 since 1619, and the starost of Borysów

Barysau

Barysaw , also transliterated Barysau, is a city in Belarus situated near the Berezina River in the Minsk Voblast.-History:...

. Radziwiłł also held the title of Reichsfürst

Fürst

Fürst is a German title of nobility, usually translated into English as Prince.The term refers to the head of a principality and is distinguished from the son of a monarch, who is referred to as Prinz...

(Imperial Prince) of the Holy Roman Empire

Holy Roman Empire

The Holy Roman Empire was a realm that existed from 962 to 1806 in Central Europe.It was ruled by the Holy Roman Emperor. Its character changed during the Middle Ages and the Early Modern period, when the power of the emperor gradually weakened in favour of the princes...

.

He married Zofia Olelkowicz Słucka

Sophia Olelkovich Radziwill

Sophia Olelkovich Radziwill was the last descendant of the family Olelkovich-Slutsk who were descended from Prince Algirdas. She was canonized by the Orthodox Church in 1983. The church of St...

 on 1 October 1600. She died in 1612, and was canonized by the Belarusian Orthodox Church as saint Sofia of Slutsk

Slutsk

Slutsk is a town in Belarus, located on the Sluch River south of Minsk. As of 2010 its population is of 61,400).-Geography:The town is situated in the south-west of its Voblast, not too far from from the city of Soligorsk.-History:...

thanks to her charity and miracles on the grave. Zofia's large estate (seven castles and palaces and some thirty-two villages) contributed to the already significant Radziwłł's wealth. His second marriage was to Elisabeth Sofie of Brandenburg, daughter of John George, Elector of Brandenburg

John George, Elector of Brandenburg

John George of Brandenburg was a Prince-elector of the Margraviate of Brandenburg and a Duke of Prussia...

, on 27 March 1613 in Berlin

Berlin

Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...

.

It was during Radziwiłł's life that the interests between his family and the state began to drift apart, as the Radziwiłłs sought to increase their wealth and power, safeguard Protestantism and support ethnically Lithuanian culture, while disregarding the public good

Public good

In economics, a public good is a good that is non-rival and non-excludable. Non-rivalry means that consumption of the good by one individual does not reduce availability of the good for consumption by others; and non-excludability means that no one can be effectively excluded from using the good...

 and putting their dynastic interests over interests of the state.

He fought against Sweden

Swedish Empire

The Swedish Empire refers to the Kingdom of Sweden between 1561 and 1721 . During this time, Sweden was one of the great European powers. In Swedish, the period is called Stormaktstiden, literally meaning "the Great Power Era"...

 in Livonia

Livonia

Livonia is a historic region along the eastern shores of the Baltic Sea. It was once the land of the Finnic Livonians inhabiting the principal ancient Livonian County Metsepole with its center at Turaida...

. Dissatisfied with the lack of material rewards, however, he joined the opposition against King Sigismund III Vasa

Sigismund III Vasa

Sigismund III Vasa was King of Poland and Grand Duke of Lithuania, a monarch of the united Polish–Lithuanian Commonwealth from 1587 to 1632, and King of Sweden from 1592 until he was deposed in 1599...

 and became one of the leaders of the Zebrzydowski's Rokosz

Zebrzydowski's Rokosz

Zebrzydowski's Rebellion , or the Sandomierz Rebellion , was a rokosz in the Polish-Lithuanian Commonwealth against King Sigismund III Vasa...

. This confederatio, an armed and legal rebellion, was aimed at weakening the king.