The first Tolkiens ever and the suffix -ien Tolkien = Tolksson?

»I do not understand why you should wish to associate my name with TOLK, an interpreter or spokesman. This is a word of Slavonic origin that became adopted  in Lithuanian (TULKAS), Finnish (TULKKI) and in the Scand. langs., and eventually right across N. Germany (linguistically Low German) and finally into Dutch. It was never adopted into English.«

(J.R.R. Tolkien, letter #349 to Mrs. E. R. Ehrardt)

Source: Wiki-de

Where is the Tolkien family name first attested? In Saxony? By the North Sea? In Western Germany?

Map with the villages where the members
of the Tolkien family occur in the 14th-16th centuries.
From Tolksdorf (Tolkynen) and Tolks to Kondradswalde and Legitten in Sambia

No, it is first attested in the form Tolkien in East Prussia in the 16th century. The first Tolkien I have ever spotted was Crispin Tolkien from Konradswalde in the Lutheran parish of Schönwalde near Königsberg (today it is Kaliningrad occupied by Russia). Here I have written about Crispin Tolkien. In the 15th and 16th centuries the same family name seems to be spelled Tolkyn. And in the 14th century members of the same family were known as the Tolk (the first one being Mathias Tolk von Merklingerode). Mrs. Ehrardt was probably right and Professor Tolkien was not...

Below I present a list of the family names with the -ien (pron. [i:]) suffix from the parish of Schönwalde, East Prussia. Below there are the family names with -ien from the years 1608-1767:

Brosien (possibly a variant of the family name Bross),
Cattien,
Dollien (also Dolin, Dolinn),
Englien (also Englin, Englyn, Anglyn)
Kadgien (also Kadgiehn)
Krepelien (also Krepelin, Krepelihn, Crepelin)
Lapsien (also Lapsin, Lapsiehn, Lipsin)
Marquien
Stadien
Tolkien (also Tolckiehn, Tolckin, Tolckyn, Tolckien, Tolkin, Tolkühn, Tollckiehn, Tholkin etc.)
Wosegien (also Wosegihn, Wosegin, Wosegyn, Wosgin, Wisgin, Bosigin)

In another parish, in Groß Legitten, we find (1668 - 1765):

Albien (also Albin, Allbien)
Bitterkien (also Bieterkien)
Bosien
Dewien (also Devin, Dewin, Dewihn)
Gerwien
Cadgien Kernckien (also Kernekin, Kernekihn, Kernekien, Kerneckin, Kerneckihn, Kerneckien, etc.)
Kervien (also Kervin, Kerwien, Kirvin)
Labbien
Powien (also Bowihn)
Tobien (also Tobin)
Tolkien (Tollckien, Tollkein)

In the neighbouring parish of Arnau we have (1668-1769):

Bordien (Bordin, Bardien, Berdien, Berdiehn)
Dromien (Dromin)
Engelien (Engelin, Engelihn)
Glaubien (Glaubin, Globin)
Kodgien (Kadjiehn, Kadejin, Kadgin, Kodgin, Kodjin, Kodjiehn, Kodijin, etc.)
Polkien (Pollkehn, Polkein, Polckein, Polkihn, Polken)
Tolkien (also Tollkiehn, Tollkien, Tolkin, Tolkiehn, Tolckien, Tolckihn, Tolckin, Tolkühn, Telkin)
Wosegien (also Wosegin, Wosigin, Wosgin, Woßgin)

The Tolkien family name can be found east of Königsberg also in the following parishes: Heiligenwalde, Quednau and Powunden (see here).

As we can see the -ien family names are not rare in the Old Prussian language area of East Prussia. What is the meaning of this suffix?

According to the German website Wiki-de the endings -ienen, -ehnen, -iehnen, -önen, -öhnen are derived from Old Prussian (Baltic) -ien and belong to the patronymic place-names (place of the offspring of the founder of that place). In the 15th century documents the village Tolksdorf (today in Polish Tołkiny) was called Tolkynen. The /y/ in the post-Luther German spelling would be written /ie/. If so, we have here *Tolkienen. According to just mentioned interpretation this place-name would mean 'a village of the heirs of Tolk', and Tolkien alone would mean 'a heir of Tolk, Tolksson, a little Tolk'. The Tolk or 'the interpreter, mediator' (Low German from East Prussia tolk < Old Prussian tulk-) who founded Tolksdorf was Matthias "Tolk" von Merklingerode (see here).

Another possibility is that Tolkien is the the German spelling of the Slavic form Tołkin. Many Polish-speaking settlers lived in the area of Tolksdorf in the 15th century. Polish Tołkin means 'belonging to Tolk' and is very common in the Slavic and post-Slavic area: from Berlin to Będzin...

It is suspected that the personal significance of the "rashbold" (German tollkühn) etymology which J.R.R. Tolkien refers to frequently and repeatedly, if sometimes obliquely, throughout his life has influenced his judgement and led him to rather significantly overstate his case in the letter to Mrs. Ehrardt (see LotR Fanatics Plaza Forum). Read about the false interpretations of the East Prussian family names here.

Teutonic knight and a guest knight during a reise in the 14th century (from Osprey)