The liner was built in Glasgow for the Russian American Line in 1912 and sailed on North Atlantic routes from Liepāja (Libau) to New York.

On one eastbound voyage in October 1913, Czar was one of ten ships that came to the aid of the burning Uranium Line steamer Volturno.

[4] Czar sailed on her maiden voyage on 30 May 1912 from Libau (present-day Liepāja, Latvia) to Copenhagen and New York,[4] arriving in the latter city on 13 June.

She replaced Lituania on the Libau – New York route, and sailed with various combinations of Kursk, Russia, Birma, and Dwinsk until July 1914.

[11] Czar sailed on her first voyage with American troops on 16 April 1918, when she departed from the Hoboken Port of Embarkation, with U.S. Navy transports Maui, Calamares, Pocahontas, El Oriente, and UK troopship HMT Czaritza.

Czar loaded troops at Newport News, Virginia, and set out on her second US convoy crossing on 14 June, sailing with American transports Princess Matoika, Wilhelmina, Pastores, and Lenape.

[13] Later that morning, the Newport News ships met up with the New York portion of the convoy—which included DeKalb, Finland, Kroonland, George Washington, Covington, Rijndam, Italian steamship Dante Alighieri, and UK troopship Vauban — and set out for France.

[14] The convoy had a false alarm when a floating barrel was mistaken for a submarine, but otherwise uneventfully arrived at Brest on the afternoon of 27 June.

[15][16] When she departed Newport News on 7 October, Czar began her last voyage ferrying American troops to France.

[20] HMT Czar arrived in the Tyne, from Murmansk last Friday (15 August 1919), with about 1,800 UK and Italian troops from the Syren Force North Russia.

[21] By late 1920 Czar had been returned to the East Asiatic Company, who placed her in service for its Baltic American Line subsidiary and renamed her Estonia.

Her last voyage for the Baltic American Line began on 31 January 1930 when she sailed from Danzig to Copenhagen, Halifax, and New York.

Sold to the Polish-owned PTTO (later Gdynia America Line), she sailed on 13 March for one more trip on the Danzig – New York route under the name Estonia.

[24] Likely because of the confusion surrounding the French surrender on 22 June, Pułaski's movements over the next days are unrecorded, but she was detained at Conakry on 8 July by Vichy authorities.

[24] On 14 August Pułaski, Kościuszko (the latest name of the former Czaritza), and Batory were chartered by the Ministry of War Transport for trooping duties and placed under the management of Lamport and Holt of Liverpool.

[24] In late June, Pułaski, loaded with 2,047 troops, sailed from Clyde to join convoy WS 9B headed for Freetown.

Leaving behind one ship at Cape Town, Pułaski and the others sailed on 30 July to their final destination of Aden, where they arrived in mid August.

[24][29] Over the next seven months, Pułaski operated in the Indian Ocean, primarily sailing between Middle Eastern and East African ports.

Departing East London on 25 June, she resumed her Middle Eastern and African runs between Aden, Suez, and Durban.

In November, the transport departed Aden and called at Basra, Bandar Abbas, and Karachi, before returning to Durban in early December.

During this span, which lasted until mid-September 1944, the ship called at Bombay twice in addition to numerous stops in Aden, Suez, Durban, and Kilindini.

Over the next months, she shuttled between Rangoon, Calcutta (where she was docked on Victory over Japan Day), Chittagong, Madras, and Colombo, arriving at the latter port for the final time on 12 September.

From Colombo she sailed into the Western Pacific for Singapore where she arrived for the first of several visits on 14 September, two days after the Japanese garrison there surrendered.

Through the end of 1945, Pułaski continued sailing between Singapore and India, making additional stops at Port Swettenham, Chittagong, Sourabaya, and Batavia.