He attended elementary school in a small parish of Saka, and later continued education in Riga Nikolai Gymnasium.

In 1904, during the Russo-Japanese War, Zemgals was mobilised and sent to the front, where he spent a year and a half and was promoted to the rank of captain.

After his return to Latvia in 1905, Zemgals became one of the creators of a new liberal newspaper "Jaunā Dienas Lapa" (New Day's Page) and proceeded to become an editor of this paper.

In July 1907, the Riga district court sentenced Zemgals to a three months long arrest for his work at "Mūsu Laiki".

When World War I began, Zemgals was once again mobilised and initially assigned to an infantry division in the middle part of Latvia, but later he was sent to Finland.

When the bolsheviks were gaining power and approaching Latvia, the Tautas Padome sent Jānis Čakste and Zemgals abroad to represent Latvian interests.

After his presidency ended, Zemgals continued his political activities and was elected in the fourth Saeima where he was a member of the foreign and finance, trade and industry commissions.