Final answer:
Ring sequences can reach back about 700 years, a fact determined using dendrochronology, which is consistent with Carbon-14 dating and helps establish historical timelines.
Step-by-step explanation:
Recent ring sequences reach back to about 700 years. This estimate is supported by the study of tree rings, which are known to represent a single year's growth. The number of rings in a cross-section of a tree trunk reveals how many years the tree has lived, with each ring indicating one year. This method, known as dendrochronology, can provide accurate dating and is often corroborated with other forms of dating such as Carbon-14 dating. In the given context, tree ring data combined with numismatic and radiocarbon dating of artifacts and remains (such as from graves FS 166 and FS 164) help to establish a timeline for historical events, like the uprising in Tàrrega.