Ion Nunweiller was born in Piatra Neamț on 9 January 1936.[1][5] He had an Austrian father named Johann Nunweiller, who settled in Piatra Neamț after World War II where he met his wife, Rozina, later they moved from Piatra Neamț to Bucharest.[6] He had six brothers, the oldest one of them, Constantin was a water polo player and the other five: Dumitru, Lică, Victor, Radu and Eduard were footballers, each of them having at least one spell at Dinamo București, they are the reason why the club's nickname is "The Red Dogs" as especially Ion and Lică were known for their aggressiveness on the field and the fact that their faces were turning red from the effort.[6][7] Ion started playing junior level football in 1950 at Progresul ICAB București, one year later moving to Dinamo București where he worked with coach Petre Steinbach, four years later starting his senior career in 1956, playing for Dinamo 6 București in Divizia B.[1][8][9]
He came back to Dinamo București where on 12 August 1956 he made his Divizia A debut in a 2–0 victory against Dinamo Bacău.[1][8] In his first seasons spent with Dinamo he scored four goals against rivalsSteaua București, including a brace in a 2–1 victory, winning his first trophy after being used all the minutes by coach Iuliu Baratky in the 4–0 win over CSM Baia Mare from the 1959 Cupa României final.[1][8][10] Ion Nunweiller helped the club win four consecutive Divizia A titles from 1962 until 1965, in the first he worked with three coaches Traian Ionescu, Constantin Teașcă and Nicolae Dumitru who gave him 26 appearances in which he scored three goals, in the following two Dumitru and Ionescu used him in 18 matches in the first and 26 in the second and in the last one he played 25 games under the guidance of Angelo Niculescu.[1][8][11] At the conquest of all these titles he was teammate with his brother Lică, at the last two in the team being his brother Radu as well.[11] He also won two more Cupa României trophies with The Red Dogs, coach Ionescu using him and his brothers all the minutes in the 5–3 victory over Steaua from the 1964 final, then in the one from 1968 Ion played the whole match which was a 3–1 over Rapid București, being coached by Bazil Marian.[1][12] He played for Dinamo in a total of 19 European Cup matches in which he scored twice and one Inter-Cities Fairs Cup game, appearing in the first European match of a Romanian team, the 3–1 victory against Galatasaray from the 1956–57 European Cup, helping the team go to the next phase of the competition where they were eliminated by CDNA Sofia.[1][13] In the 1963–64 European Cup edition, he scored once in a 2–0 victory against East Germany champion, Motor Jena which helped the club advance to the next phase where they were eliminated by Real Madrid against whom he scored in a 5–3 loss and also appearing in a historical 2–1 win over Inter Milan in the 1965–66 edition who were the winners of the last two seasons of the competition.[1][5][14][15][16] For the way he played in 1966, Nunweiller was placed fifth in the ranking for the Romanian Footballer of the Year award.[17]
Afterwards Nunweiller spent two seasons at Fenerbahçe from 1968 until 1970, making him one of the first Romanians to play professional football in Turkey.[14][18] During his period spent in Turkey, Nunweiller played four games in the 1968–69 European Cup where he helped Fenerbahçe eliminate the champion of England, Manchester City and in his second season spent at the club he was coached by Traian Ionescu and was teammate with Ilie Datcu, all of them previously working together at Dinamo, winning together the Turkish Super League title, a TSYD Cup in which he scored the only goal from the final against Beşiktaş, also being elected the best foreign player of the Turkish League 1969–70 season.[1][14][18][19]
In 1970 he returned to Dinamo and in his first season he won another title, playing alongside his brother Radu, coaches Dumitru and Ionescu using Ion in 20 games.[1][8][11] Ion Nunweiller made his last Divizia A appearance on 12 December 1971 in a 2–1 away loss in front of Argeș Pitești, having a total of 279 matches with 19 goals scored in the competition.[1][8][14]
After ending his playing career in 1972, Ion Nunweiller became the head coach of Dinamo București, managing to win the title in his first season, one of his players being his brother, Radu.[5][11][14][21][23][24] Together with his brother, they won another title in the 1974–75 season but this time Ion was the assistant coach of Nicolae Dumitru.[11][21] As head coach he led The Red Dogs to a third title in the 1976–77 season, having his brother Lică as his assistant coach.[11][21][25]
In the following years he qualified Flacăra Moreni to the 1989–90 UEFA Cup, had an experience in Turkey at Bursaspor and obtained the first ever promotion to Divizia A of his hometown team Ceahlăul Piatra Neamț.[14][21] Nunweiller has a total of 374 matches as a manager in the Romanian top-division, Divizia A consisting of 163 victories, 76 draws and 135 losses.[26]
On 25 March 2008, Ion Nunweiller was decorated by the president of Romania, Traian Băsescu for all of his achievements as a football coach, and for forming young generations of future champions with Ordinul "Meritul Sportiv" — (The Order "The Sportive Merit") class III.[27]
Death
Ion Nunweiller died on 3 February 2015 at age 79 in a hospital from Pitești.[14][21][23][24][28][29] He was buried in a cemetery from Albota, his coffin being wrapped up in the flags of Dinamo București and Fenerbahçe.[24][28][29] After his death, his former Dinamo teammate, Cornel Dinu talked about him:"He was the creator of the symbol of The Red Dogs and the main pillar of resistance through which the great team was built from the beginning of the 60s. A player who had many moments in which he showed heroism in blocking the opponent and making sure that his own defense was not overtaken. He was an indisputable leader of that period and achieved good things, as a coach, after the 70s, also in the position of leader of Dinamo. Both as a player and as a coach, he transmitted this spirit of fight and loyalty in the service of the team."[23]