Petr Bratský was born on April 8th 1955 in the western Bohemian town of Klatovy. The partial thaw of the communist totalitarianism with its peak in 1968 enabled him to become a member of the restored Boy Scout movement that impacted the whole of his life. After another prohibition and dispersal of the Boy Scout organization by the communists he continued with other members of his group in illegal activities. It resulted in persecution of all the people engaged, manifested prevailingly by preventing them from further studies. After completing the elementary school in 1970 he was allowed to study only at a Railway Training Institution in Karlovy Vary, a year later he could transfer to a Technical College of Transport in Pilsen. After completing the studies at the college for a year and a half he worked as a train dispatcher of the Czech Railways in Lužany near Klatovy.

In 1977 he was admitted to the University of Transport and Telecommunications in Žilina in Slovakia where he specialized in railroad transport economics. After five years he graduated and acquired the title of engineer. As a graduate he joined the Transport Development Center Prague (DRS); however, soon after he was called up for a one-year military service in Prague-Ruzyně. Then he returned to DRS and for seven years he worked as an independent expert assistant on forecast studies for the Federal Ministry of Transport. In 1986 he moved to the newly built Prague housing estate Lužiny in the South-Western City (JZM).

During the Velvet Revolution in 1989 Petr Bratský was the co-founder of the Civic Forum in Lužiny and in the first free communal elections in the fall of 1990 he was elected the first mayor for the Civic Forum of the Prague-Stodůlky Municipality (since 04/01/1991 Prague South-Western City). Concurrently he was elected a member of the Prague Capital Municipal Office (ZHMP). In 1991 he was also one of the founding members of the Civic Democratic Party (ODS) and is its member to date. Throughout his first four-year term in the mayor office he played an important role in finishing another section of the underground B line (Metro) from Nové Butovice via JZM to Zličín, improving the environment on the local housing estates as well as in making the city quarter with fifty thousand inhabitants a firm basis for the future new municipal area. In 1994 he was re-elected the mayor of the then renamed Prague 13 and also started another term of office as a member of ZHMP. He was re-elected to both offices for the third time in 1998; in the elections to ZHMP he obtained the largest number of votes of all the elected candidates in the whole capital city.

In the following terms he supported especially the urban development of Prague 13, building and reconstruction of children and playing fields. The first two extensive stages of building the Central Park were materialized. Support and viability of civil society, associations, clubs, units and organizations on the South-Western City housing estates was enhanced. Special attention was paid to younger as well as older generation. An important task was to create the basis and continuously strengthen the nascent common identity of inhabitants of the "green field" town, inhabitants who had come from various places of the country as well as from abroad. New traditions were laid down (awarding silver medals and honorary citizenship to valued inhabitants), the external signs of the new municipal area established (coat of arms, flag, insignia, fanfare). Petr Bratský initiated publishing of a local magazine, cable TV broadcasting, stood at the birth of many traditional public events (Carnival, Witch burning, The Mayor Suspenders Hockey Ball Tournament, Little Bell of Butovice, Children Olympic Games and many others). And it is probably these achievements and results that might have lead voters to not elect him the senator for Prague 5 and 13 in the historically first elections for the Senate in the fall of 1996. Although in the first round he beat all of his rivals with more than 38% of votes, in the second round his rival candidate Michael Žantovský (ODA) advancing from the second place eventually won.

After the communal elections in 1998 he was one of the hot candidates for the post of the Prague Lord Mayor, but he preferred to remain in the office of a mayor and in 1998-2001 he also held the office of the Chairman of the Club of Representatives of ODS in ZHMP. In 2 002 and again in 2006 he was elected a Deputy for the Prague electoral district. In the Chamber of Deputies he works as a member of the Science, education, culture, youth and sports committee and member of the Committee on European Affairs. Since 2007 he is the head of the Czech Permanent delegation to the Parliamentary Assembly of the Organization for Security and Cooperation in Europe.
 

Throughout the whole of 1970s and 1980s Petr Bratský (having the nickname of Bráca) was engaged in illegal scouting in a rover camp, organized woodman camps and similar activities. He and his later wife Ludmila played in several country bands and achieved appraisal on the legendary PORTA festival (e.g. made it to the final in 1979). Petr Bratský plays mainly guitar and contrabass and also sings. On the literary stage he won the tramp literary contest Trapsavec ("Tramp writer") in 1983 and he also wrote and himself bound a collection of love poems for his wife "Střípky lásky (Fragments of Love)" (1988). He likes sports, especially cycling, hiking, swimming, tennis, formerly also basketball and athletics.

After moving to the South-Western City in 1987 he founded a Tourist Youth Club (T.O.M.) Táborník (Camper) at the local school and TJ Lokomotiva Praha (Sports Association), took part in founding and managing Children Sports Club Motýlek (Butterfly) at TJ Motorlet. In the first weeks after the Velvet Revolution he was the co-founder of a Boy Scout Center VATRA in the South-Western City. To date he manages his 96th group Šipka (Arrow) and organizes regular summer camps in Šumava - mountains in the south-western Bohemia.

In the 1990s he initiated formation of an informal "band of the Prague mayors" the members and musical cast of which often change, most obviously after elections. Based on this idea in the spring of 2002 Petr Bratský intended to publish a unique CD of "Songs of the Prague mayors" with the old Prague songs devoted to particular districts and quarters.
 

In 1984 Petr Bratský married Ludmila (maiden name Kotálová, graduated at the University of Economics in Prague, engineer of economics, comes from Klatovy, too). He has two sons - Petr (born in 1986, now studying at the University of New York in Prague) and Pavel (born in 1988, now studying at the High School).

Petr Bratský has a sister Pavla who emigrated from the socialist Czechoslovakia in 1982, a fact that deepened persecution of the "politically unreliable" family by the communist authorities. He reunited with his sister only after 1989, upon her request several years later he managed her wedding ceremony as the mayor in the newly opened metro station Lužiny. Pavla now lives with her husband Fred Reed in Florida, USA.