Medieval Transylvania

The status of medieval Transylvania is a very generous topic.

From the things which caused this paranthesis related to Gesta Hungarorum, I certainly don't agree with a full of extent of Hungarian control over Transylvania as they arrived due to several reasons (the stories from GH aside). I will list few of them:

- Written sources: In 10th century we have the testimony of Constantine Porphyrogenitus which says that between Tourkia and Patzinakia there's a 4 days journey. That suggests an uncontrolled Transylvania (not by Magyars, Pechenegs or other political power known/relevant to Byzantines).

- Archaeology: the early Magyar sites do not cover the entire territory of Transylvania but several areas - the western plains and along some large valleys like the one of Mures/Maros.

- Archaeology and numismatics: there are some coins which characterise the early Magyar sites - the western coins or the Arab dirhems (until 930 or so) most of them probably being used for decorative purposes rather than trade. There were no Arab dirhems found in Transylvania (they were mostly found in the north-east of today Hungary) and only one western coin from the period 886-955, when the Magyars were raiding heavily. It's a German coin issued by Berthold, count of Bayern (938/9-947). Needless to say, there are plenty of findings in Pannonia

Indeed, the possessions of Hungarian Kingdom in Transylvania are also studied from the point of view of gyep� (lat: indagines), and these borders are interrupted from place to place by kapu (lat. porta; and perhaps also porcz derived from the Romanian por�i). But beyond these borders, sometimes there are solitudines, terrae desertae, sometimes other political spaces (which sometimes can be bound by vassalages or other obedience acts to the royal crown of Hungary).

During X-XIVth century the Hungarian kingdom (at least in Transylvania) expanded this border and one process was a conquest of these "deserted" spaces (the royal acts are evidences from 12-13th century onward, the extrapolation belongs to me and we can discuss it; what it should be noted is that the discussion about royal rights makes sense only after 13th century since we have the written acts, before that there's less evidence about the nature of the conquest). The royal crown sometimes gives such border territories to various individuals or groups to take care of them, and thus expand the kingdom. For instance, in Maramures/Maramoros, an act (1445) mention the possessions of some local knezes which owned their lands from the immemorial times as they were given the lands in forests and inhabited mountainous places. They cleared and took care of those lands and the Hungarian king recognized their possession. In 13th century the Teuton knights are settled in the deserted land of Burzenland (note: these mentions do not support the extermist hypotheses that these lands were really uninhabited, the acts which confirm the Teuton ownership mention clearly they are given the lands but also their inhabitants: homines, qui terram ipsam inhabitabant). In the same 13th century, in Sibiu/Hermannstadt area the Germans are settled in an Insula Christiana in a deserted land (in illo solo deserto). Stelian Brezeanu has several studies on medieval Transylvania (mostly focused on the analysis of toponyms, but not only) where he tries to discover the ethnical, social and political realities of those centuries. The advancement of gyep� and the colonization/administration of terrae desertae are among the subjects covered by his work.

You have to learn to take a more flexible attitude and to understand historians can make some valid and well-justified points but sometimes also more hazardous ones. Also, you should read more extensively before drawing your own conclusions.

Al. Madgearu - for instance - has a series of works on the chronicle of Anonymous and on the alleged Transylvanian political entities where he attempts to synchronize this written source with other sources. Sometimes he has persuassive and admirable arguments, but we have to be aware of his declared purpose and consequently of his possible bias.
However, in this case, the mention of "voivodat" in his works has a justification (though not a very solid one). As Madgearu himself notes in a study named "Geneza si evolutia voievodatului Banatean din secolul al X-lea":

St. Brezeanu in "O istorie a Bizantului" (A history of the Byzantium) arguing about the 10th century Transylvania's space names these characters "duci" (dukes) and interprets the testimony of GH as a mentality, a belief in a subordination of this area to the political and religious influence of the Constantinople. He also characterizes the autochtonous culture of 10th-11th century as a "inceput de organizare politico-militara a populatiilor romanilor si slavilor, care coexista in acelasi spatiu" (the beginning of a political and military organization of the Romanians and the Slavs). Nothing about voivods, nothing about knyazs.
More relevant on the topic is Brezeanu's study "Inceputurile romanilor si maghiarilor in Transilvania. Traditie savanta si memorie populara medievala" (The beginnings of Romanians and Hungarians in Transylvania. Medieval scholarly tradition and folk memory). The land of Gelou is "ducat" (dukedom) and "tara ultrasilvana" (land/terra ultrasilvana). Gelou and Glad are "dukes". Again, not voivods, not knyazs.

 As you can see, Brezeanu doesn't subscribe to Madgearu's "common usage". So much about voivodship in GH.