Seinai is a town in southern Suvalkija with a large Lithuanian population, which eventually was included in Poland. In World War One, it was taken by 42. Infanterie-Division on February 14, 1915. After the German withdrawal from Russia at the end of 1918, Seinai was first guarded by the Grenzschutz, esp. Brigade Grodno, and later was administered by Lithuanians until forced out by Polish troops on August 23, 1919. During the Russo-Polish war Seinai was retaken by Lithuanians on July 19, 1920 and held against the Poles until August 31, 1920.
In the czarist period Seinai had a post office Sejny. During German occupation a branch of the Postgebiet Ob.-Ost, Sejny, was opened on April 20, 1916 and closed down on December 1, 1918. In the first half of 1919 members of the Grenzschutz mainly used Frw. Feldpost 3007 stationed in Gardinas (Grodno).
As a result of post-war battles and changing occupations, there are two separate periods of the Lithuanian post office of Seinai: first – about 7 months in 1919, and second – a few weeks in 1920.
A mandate to set up a Lithuanian post office was issued, as early as January 11, 1919, to Domininkas de Rameris, but it is not clear whether he took up the appointment, for on February 1, he was formally replaced by Antanas Žekis. He in turn was soon replaced on February 13, 1919 by Juozas Sodaitis who stayed on as effectual postmaster until Seinai was occupied by Polish troops on August 23, 1919. Postmaster Juozas Sodaitis and postman Jonas Karlikauskas then evacuated to Alytus.
When Seinai was regained by the Lithuanians on July 19, 1920, as įgaliotinis was appointed Aleksandras Pavilionis, effective August 1, 1920, who had been attached to Šiauliai P.O. On his transfer to Kaunas (telephone and telegraph branch) he was replaced by Kazys Prokuraitis. As a result of Polish re-occupation of Seinai on August 31, 1920, Kazys Prokuraitis was later appointed postmaster of Lazdijai.
For stamps, Seinai had Second Vilnius Issue followed by First and Second Kaunas and Fourth Berlin Issue. It is not known if it had First Vilnius Issue.
In the absence of a regular postmarker Seinai resorted to manuscript cancellation. Early mail shows a diagonal cross supplemented by place-name and date.
Later cancellations show only date and place.
A standard postmarker was supplied in early May 1919.
Having no regular registration cachet, Seinai made use of home-made etiquettes or MS imitation frames. Registered mail, even from members of the Grenzschutz addressed to Germany, was first sent to Kaunas.
During the occupation of Seinai by Polish troops for the first time on August 23, 1919, some of the Lithuanian postal equipment had been left behind. The Lithuanian postmarker was adapted to Polish use by erasing part of the Lithuanian spelling. The first version shows simply “SEIN…”, .the subsequent version was improved by attaching a smaller size “y” which is not always visible. The adapted postmarker was used as late as 1924 if not later.
The second period of the Lithuanian post office of Seinai in 1920 lasted for only about the month of August. So far no items or postal markings have come to light from this period.
Known provisional markings:
Cancelling by MS diagonal cross plus date and place:
10 / III / 1919 card to Germany, Vilnius II 20, Kaunas I 20 [colln. Lapas]
Cancelling by MS date and place:
24 / III / 1919 cover to Kaunas, Kaunas I 30 [colln. Bubnys]
3 / IV / 1919 block of 4, Vilnius II 10 [colln. ?]
1 / V / 1919 card to Germany, Vilnius II 20, Kaunas I 20 [colln. Brazdeikis]
1 / V / 1919 single, Vilnius II 20 [colln. Doniela]
1 / V / 1919 single, Kaunas I 10 [colln. Wilson]
Provisional registration markings:
16 10 / IV 1919 reg. cover to Germany, Vilnius II 20, 40 x2 [colln. Doniela]
33 3 / V / 1919 reg. cover to Germany, Vilnius II 50, Kaunas II 50 [colln. Norton jr]
Polish adaptation of “SEINAI” showing “SEIN” or “SEINy”:
11. II. 20 cover ? to a foreign destination [colln. ?]
25. III. 20 “SEIN” card to Skierniewice [colln. Lapas]
rds 21. IV. 20 “SEINy” card from Skierniewice [colln. Doniela]
[1923 ?] “SEINy” reg. cover to USA [colln. ?]
25. IV. 24 “SEIN” reg. cover to USA [colln. ?]
rds 27. XI. 24 “SEIN” and “SEINy” reg. cover Sejny to Sejny [colln. ?]