The administration of a decedent's estate involves a series of separate proceedings, each of which is intended to be final

Each can be attacked directly by appeal, or by some motion authorized by law for the purpose, or, perhaps, by bill in equity, but an attack made in a different proceeding in the same estate would clearly be collateral

For later cases in California, and Iowa as to the recitals in judgments of courts of general jurisdiction, and presumptions which arise upon collateral attack

An order admitting a will may be appealed from, or the admission of the instrument to probate may be contested, and the validity of the will attacked within one year after such probate, but an attack on the order, or a contest of the validity of the whole or of a part of the will, is not a direct attack merely because made or instituted in some proceeding connected with the …

Each separate proceeding in the probate of an estate culminating in a decree authorized by the Legislature and thus within probate jurisdiction, results in a judgment and, when it becomes final, that judgment is binding on all interested parties, as to the matters that it determines

We think we may safely say that a claim which has been duly presented to an administrator of an estate, by him allowed, by the probate court approved and allowed, and by a decree of the probate court approving and allowing a filed claim on the hearing of an account is, when the decree approving the account becomes final, res judicata

We must assume therefore that Alameda County has not acquired jurisdiction over the action on the bond, and no question of priority is presented

A presumption of regularity applies to such proceedings so that they are not susceptible to collateral attack except for defects showing upon the face of the record

In the same case the court also said (p. 756): "Absence of a personal notice in such proceedings does not deprive any person in interest of any of his constitutional rights

—to effect that many proceedings are authorized by the title of the code relating to administration of estates. 6.