Piesiewicz studied law at
Warsaw University and began practicing in 1973. Through the late 1970s he became increasingly involved in political cases, defending opponents of the
Communist regime, serving as a legal advisor for
Solidarity, and assisting in the successful prosecution of the murderers of
Jerzy Popiełuszko. In 1982, he met the film director
Krzysztof Kieślowski, who was planning to direct a
documentary on political
show trials in Poland under
martial law. Piesiewicz agreed to help, though he doubted whether an accurate film could be made within the constraints of the judicial system; indeed, the filmmakers found that their presence in court seemed to be affecting the outcomes of cases, often improving the prospects of the accused, but making it hard to capture judicial abuses. Kieślowski decided to explore the issue through fiction instead, and the two collaborated for the first time as writers on the feature film
No End, released in 1984. Piesewicz returned to his law career, but remained in touch with Kieślowski and three years later persuaded him to create a series of films based on the
Ten Commandments. This series,
Dekalog, explored the filmmakers' mutual interest in
moral and
ethical dilemmas in contemporary social and political life, and achieved (belated) critical acclaim around the world. Their later collaborations,
The Double Life of Véronique and
Three Colours (
Blue,
White,
Red), focused on metaphysical questions of personal choice and appeared relatively apolitical, though the latter series was based on Piesiewicz's idea of dramatizing the
French political ideals of liberty, equality, and fraternity in the same way they had previously dramatized the Ten Commandments. Piesiewicz was credited as co-writer on all of Kieślowski's projects after
No End, the last of which was
Nadzieja, directed by Stanislaw Mucha after Kieślowski's death. He has begun writing a new series of films,
The Stigmatised; the first of these,
Silence, was directed by
Michał Rosa and released in 2002. ==Career in politics==