subjects, such as the contemporary religious upheaval portrayed by Albrecht Dürer. Later, the works of Pieter Bruegel influenced artists to paint scenes of daily life rather than religious or classical themes. It was also during the Northern Renaissance that Flemish brothers Hubert and Jan van Eyck perfected the oil painting technique, which enabled artists to produce strong colors on a hard surface that could survive for centuries. A feature of the Northern Renaissance was its use of the vernacular in place of Latin or Greek, which allowed greater freedom of expression. This movement had started in Italy with the decisive influence of Dante Alighieri on the development of vernacular languages; in fact the focus on writing in Italian has neglected a major source of Florentine ideas expressed in Latin. The spread of the printing press technology boosted the Renaissance in Northern Europe as elsewhere, with Venice becoming a world center of printing. Poland An early Italian humanist who came to Poland in the mid-15th century was Filippo Buonaccorsi. Many Italian artists came to Poland with Bona Sforza of Milan, when she married King Sigismund I in 1518. This was supported by temporarily strengthened monarchies in both areas, as well as by newly established universities. The Polish Renaissance lasted from the late 15th to the late 16th century and was the Golden Age of Polish culture. Ruled by the Jagiellonian dynasty, the Kingdom of Poland (from 1569 known as the Polish–Lithuanian Commonwealth) actively participated in the broad European Renaissance. The multi-national Polish state experienced a substantial period of cultural growth thanks in part to a century without major wars – aside from conflicts in the sparsely populated eastern and southern borderlands. The Reformation spread peacefully throughout the country (giving rise to the Polish Brethren), while living conditions improved, cities grew, and exports of agricultural products enriched the population, especially the nobility (szlachta) who gained dominance in the new political system of Golden Liberty. The Polish Renaissance architecture has three periods of development. The greatest monument of this style in the territory of the former Duchy of Pomerania is the Ducal Castle in Szczecin. Portugal Although Italian Renaissance had a modest impact in Portuguese arts, Portugal was influential in broadening the European worldview, stimulating humanist inquiry. Renaissance arrived through the influence of wealthy Italian and Flemish merchants who invested in the profitable commerce overseas. As the pioneer headquarters of European exploration, Lisbon