force. In the mid-eighth century, Emperor Constantine V (r.741–775) had created
new crack regiments, the tagmata (sing. tagma). These were mobile troops, not tied
to any theme. Many were composed of cavalry, the elite of fighting men; others—
infantry, muleteers—provided necessary backup. At first deployed largely around
Constantinople itself to shore up the emperors, the tagmata were eventually used in
cautious frontier battles. Under the ninth- and tenth-century emperors, they helped
Byzantium to expand.
To the west, in the Balkans, Emperor Nicephorus I (r.802–811) remodeled the
old thematic territories and added new ones. Settled by immigrant Slavs as well as
native Greeks, the Balkans presented an alluring prize for both the Byzantines and
the Bulgars. Moving into Slavic territory, Nicephorus tried to take Sardica (today
Sofia, Bulgaria), which had long been outside Byzantine control, but his soldiers
mutinied when the emperor asked them to rebuild the city. To secure at least the
northern border of the area, Nicephorus uprooted thousands of families from
Anatolia and sent them to settle in the Balkans.
Still keen to knock out Bulgarian power in the region, Nicephorus marshaled a
huge army. Escorted by the luminaries of his court, he plundered the Bulgarian
capital, Pliska, and then coolly made his way west. But the Bulgarians blockaded his
army as it passed through a narrow river valley, fell on the imperial party, and killed
the emperor. The toll on the fleeing soldiers and courtiers was immense. Theophanes
the Confessor, who detested both Nicephorus (because of his iconoclastic policies)
and the Bulgars, may well have made up the story that Khan Krum (r.803–814)
covered Nicephorus’s skull with silver and turned it into a ceremonial drinking cup,
for it cast a bad light on both khan and emperor. But it was a good metaphor for
Byzantium’s difficulties. Further Byzantine defeats in the region in the late ninth
century led to yet more shuffling of themes. The end result may be seen in Map 3.1,
to which Map 2.1 on p. 40 (Byzantium at its smallest) should be compared.
