Pangalos was born on the island of Salamis on 11/23 January 1878.
His mother was descendant of the local Arvanite fighter of the Greek Revolution, Giannakis Meletis (Hatzimeletis), while his paternal side came from an aristocratic family of Kea island.

He graduated from the Greek Army Academy on 16/29 July 1900 as an Infantry Second Lieutenant, and continued his studies in Paris, France.

During the Balkan Wars of 1912–13 he served as a staff officer in the 6th Infantry Division.
He was head of the forces that entered Sidirokastro (Demir Hisar) during the second Balkan war.

In 1916 he joined Eleftherios Venizelos' Provisional Government of National Defence against King Constantine I, and was tasked with recruiting the 9th Cretan Regiment for the new government.
He did not have a chance to lead it to battle though, because when King Constantine abdicated and Venizelos took over the governance of all of Greece in June 1917, he was appointed chief of the personnel department in the Ministry of Military Affairs.
In early 1918 he went to the front as Chief of Infantry of the 1st Infantry Division in the Strymon sector of the Macedonian front.
In late 1918 he was appointed chief of staff of the General Headquarters, holding the post until the electoral victory of the pro-royalist and anti-Venizelist United Opposition in November 1920, when he was dismissed from the army.

In 1922, Pangalos supported the 11 September 1922 Revolution, led by Nikolaos Plastiras, which abolished the monarchy and declared the Second Hellenic Republic, and played a major role in the rapid establishment of the regime in Athens, while Plastiras and the army were still sailing from Chios.
His first job was to prosecute a number of prominent pro-monarchist government leaders by military court in what became known as the Trial of the Six.
On 14/27 November he was named Minister for Military Affairs and tasked with reorganizing the Greek army in Macedonia and Thrace, as the war with Turkey was not over, and an attack in the region was feared to be imminent.
The reorganization of the "Army of Evros", which he commanded from mid-December, was so successful that the Greek High Command prepared for a possible advance into Eastern Thrace in the face of the Turkish demands in the Lausanne peace talks.
The military threat posed by Pangalos' army helped the Turks back down, and the Treaty of Lausanne was signed.

A staunch nationalist, Pangalos objected to the terms of the treaty, and declared that his troops would attack Turkey nonetheless in order to block the deal.
He was forced to resign, but his stance made him popular with the many segments of Greek society that objected to the treaty.
During the period of political instability that followed, Pangalos jumped into the fray, gaining and losing a number of ministerial positions as governments came and went.

He assisted in the suppression of the failed Leonardopoulos–Gargalidis coup d'état attempt in October 1923, and was elected to Parliament for Thessaloniki in December.
He was appointed Minister for Public Order in the cabinet of Alexandros Papanastasiou on 31 March 1924, holding the post until 18 June, when he became once more Minister for Military Affairs, retaining the post until the cabinet's resignation on 25 July 1924.
Pangalos was born on the island of Salamis on 11/23 January 1878. His mother was descendant of the local Arvanite fighter of the Greek Revolution, Giannakis Meletis (Hatzimeletis), while his paternal side came from an aristocratic family of Kea island.
He graduated from the Greek Army Academy on 16/29 July 1900 as an Infantry Second Lieutenant, and continued his studies in Paris, France.
During the Balkan Wars of 1912–13 he served as a staff officer in the 6th Infantry Division. He was head of the forces that entered Sidirokastro (Demir Hisar) during the second Balkan war.
In 1916 he joined Eleftherios Venizelos' Provisional Government of National Defence against King Constantine I, and was tasked with recruiting the 9th Cretan Regiment for the new government. He did not have a chance to lead it to battle though, because when King Constantine abdicated and Venizelos took over the governance of all of Greece in June 1917, he was appointed chief of the personnel department in the Ministry of Military Affairs. In early 1918 he went to the front as Chief of Infantry of the 1st Infantry Division in the Strymon sector of the Macedonian front. In late 1918 he was appointed chief of staff of the General Headquarters, holding the post until the electoral victory of the pro-royalist and anti-Venizelist United Opposition in November 1920, when he was dismissed from the army.
In 1922, Pangalos supported the 11 September 1922 Revolution, led by Nikolaos Plastiras, which abolished the monarchy and declared the Second Hellenic Republic, and played a major role in the rapid establishment of the regime in Athens, while Plastiras and the army were still sailing from Chios. His first job was to prosecute a number of prominent pro-monarchist government leaders by military court in what became known as the Trial of the Six. On 14/27 November he was named Minister for Military Affairs and tasked with reorganizing the Greek army in Macedonia and Thrace, as the war with Turkey was not over, and an attack in the region was feared to be imminent. The reorganization of the "Army of Evros", which he commanded from mid-December, was so successful that the Greek High Command prepared for a possible advance into Eastern Thrace in the face of the Turkish demands in the Lausanne peace talks. The military threat posed by Pangalos' army helped the Turks back down, and the Treaty of Lausanne was signed.
A staunch nationalist, Pangalos objected to the terms of the treaty, and declared that his troops would attack Turkey nonetheless in order to block the deal. He was forced to resign, but his stance made him popular with the many segments of Greek society that objected to the treaty. During the period of political instability that followed, Pangalos jumped into the fray, gaining and losing a number of ministerial positions as governments came and went.
He assisted in the suppression of the failed Leonardopoulos–Gargalidis coup d'état attempt in October 1923, and was elected to Parliament for Thessaloniki in December. He was appointed Minister for Public Order in the cabinet of Alexandros Papanastasiou on 31 March 1924, holding the post until 18 June, when he became once more Minister for Military Affairs, retaining the post until the cabinet's resignation on 25 July 1924.
Theodoros Pangalos (general)