This article is intended as a survey, updating earlier surveys in the area. For completeness of the presentation of both particular questions and the general area, it also contains material on closely related topics such as traceable, pancyclic and hamiltonian-connected graphs and digraphs. Corollary 3 [4] Let G be a graph of order n with δ(G) ≥ (2n − 1)/3 and suppose n ≥ n 1 + n 2 +. .. + n k where n i ≥ 3 for all i. Then G contains the vertex disjoint union of the cycles C n 1 ∪ C n 2 ∪. .. ∪ C n k. Clearly then, any such graph contains any 2-factor we would want and hence provides a strong analogue to Dirac's theorem. I should mention that Alon and Fischer [6] also provided a solution to the Sauer-Spencer conjecture (δ = 2n/3). Their result used work dependent on the regularity lemma and thus holds only for large graphs. Related to the last result is another old conjecture due to El-Zahar [95]. Conjecture 2 Let G be a graph of order n = n 1 + n 2 +. .. + n k with δ(G) ≥ k i=1 ⌈n i /2⌉, then G contains the 2-factor C n 1 ∪. .. ∪ C n k. Note that the graph K s−1 + K ⌈ n−s+1 2 ⌉,⌈ n−s+1 2 ⌉ has minimum degree (n + s − 1)/2 but contains no s vertex disjoint odd length cycles. Thus, the conjecture is best possible. El-Zahar [95] provided an affirmative answer to the case k = 2, while Dirac's Theorem handles k = 1. Recently, Abbasi [1] announced a solution for large n using the regularity lemma. It would still be interesting to find a solution to this beautiful conjecture for all n. It should be noted that Corrádi and Hajnal [87] provided an affirmative answer to the El-Zahar conjecture for the case that each n i = 3 An old conjecture of Erdös and Faudree [102] generalizes the Corrádi-Hajnal theorem in another direction. Conjecture 3 Let G be a graph with order n = 4k and δ(G) ≥ 2k, then G contains k vertex disjoint 4-cycles. Alon and Yuster [8] proved that for any ǫ > 0, there exists k 0 such that if G has order 4k and δ(G) ≥ (2 + ǫ)k with k ≥ k 0 , then G contains k disjoint 4-cycles. In [207], a near solution was provided by Randerath, Schiermeyer and Wang.